像这样的

  <script>
   let bfJs = document.getElementsByClassName('bf_js')[0]
   let mainData = `<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/1.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/2.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/3.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/4.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/5.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/6.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/7.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/8.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/9.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/10.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/11.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/12.jpg" /></p>
<p>
 <img src="/static/images/a2.jpg" title="/pic-class/dada1a7eeef39be0e12026293f1faa44/13.jpg" /></p>
`
 
   if (mainData.indexOf('title=')==-1) {
    console.log(mainData.indexOf('/pic-class/'));
    if (mainData.indexOf('/pic-class/')!==-1) {
     let regPicObj = new RegExp('/pic-class/', "g");
     var newstr=mainData.replace(regPicObj,fullURL+'pic-class/');        
     bfJs.innerHTML = newstr
     console.log(newstr);
    }else if (mainData.indexOf('/image/')!==-1) {
     let imageObj = new RegExp('/image/', "g");
     var newstr=mainData.replace(imageObj,fullURL);        
     bfJs.innerHTML = newstr
     console.log(newstr);
    }
   }else{
    bfJs.innerHTML = mainData
   }
   
 
   // 图片域名
   if (fullURL) {
    let strTitlea = document.getElementsByClassName('bf_js')[0].getElementsByTagName('img')
 
    let searchTextc = window.location.origin+'/image/'
    let searchClass = window.location.origin+'/pic-class/'
    let regExpc = new RegExp(searchTextc, "g");
    let regPicExpc = new RegExp(searchClass, "g");
 
    for (let index = 0; index < strTitlea.length; index++) {
     let html = strTitlea[index].src;
     let titleData = strTitlea[index].title
     let lvchaHtml = '';
     let lvchaPicHtml = '';
     if(titleData){
      titleData = window.location.origin+titleData
      if (titleData.indexOf(searchTextc)!=-1) {
       lvchaHtml = titleData.replace(regExpc,fullURL);//将找到的关键字替换，加上highlight属性； 
       strTitlea[index].src=lvchaHtml; 
      } else if (titleData.indexOf(searchClass)!=-1) {
       lvchaPicHtml = titleData.replace(regPicExpc,fullURL+'/pic-class/');//将找到的关键字替换，加上highlight属性； 
       strTitlea[index].src=lvchaPicHtml;
      }
     }else if(html){
      if (html.indexOf(searchTextc)!=-1) {
       lvchaHtml = html.replace(regExpc,fullURL);//将找到的关键字替换，加上highlight属性； 
       strTitlea[index].src=lvchaHtml; 
      } else if (html.indexOf(searchClass)!=-1) {
       lvchaPicHtml = html.replace(regPicExpc,fullURL+'/pic-class/');//将找到的关键字替换，加上highlight属性； 
       strTitlea[index].src=lvchaPicHtml;
      }
     }
    }
   }
  </scrip