我不熟悉json。你在使用regex时遇到了问题，我愿意帮助你。你可以试着跟着regex。

("bannerIds".*?\[)[\s\S]+?(\])

细节： ("bannerIds".*?\[) ：组1-捕获
"bannerIds": [ [\s\S]+? ：尽可能少地匹配任何空白字符和任何非空白字符 (\]) ：第2组：捕获 ] 演示
我还尝试在java上运行代码。

String str = "\"locationIds\": [\n"
  + "\t\"london\",\n"
  + "\t\"scotland\",\n"
  + "\t\"wales\"\n"
+"],\n"
+"\"bannerIds\": [\n"
+"\t\"red banner\",\n"
+"\t\"blue\"\n"  
+"],\n"
+"\"regionIds\": [\n"
+"\n"        
+"],\n";

  System.out.println("before replace");
  System.out.println(str);
  String result = str.replaceAll("(\"bannerIds\".*?\\[)[\\s\\S]+?(\\])", "$1$2");
  System.out.println("after replace");

  System.out.println(result);

结果：

before replace
"locationIds": [
    "london",
    "scotland",
    "wales"
],
"bannerIds": [
    "red banner",
    "blue"
],
"regionIds": [

],

after replace
"locationIds": [
    "london",
    "scotland",
    "wales"
],
"bannerIds": [],
"regionIds": [

],