需要先判断是否有root权限，可通过下面这个方法去进行判断

// 判断是否有root权限
    public static boolean isRoot() {
        PrintWriter PrintWriter = null;
        Process process = null;
        try {
            process = Runtime.getRuntime().exec("su");
            PrintWriter = new PrintWriter(process.getOutputStream());
            PrintWriter.flush();
            PrintWriter.close();
            int value = process.waitFor();
            //0代表成功  1代表失败
            return value == 0 ? true : false;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (process != null) {
                process.destroy();
            }
        }
        return false;
    }

有root权限后，用pm install 命令进行安装

// 静默安装
    private static void silenceInstall(String apkPath) {
        PrintWriter PrintWriter = null;
        Process process = null;
        try {
            process = Runtime.getRuntime().exec("su");
            PrintWriter = new PrintWriter(process.getOutputStream());
            PrintWriter.println("chmod 777 " + apkPath);
            PrintWriter
                    .println("export LD_LIBRARY_PATH=/vendor/lib:/system/lib");
            PrintWriter.println("pm install -r " + apkPath);
            //包名 + 你要拉起的activity
            PrintWriter.println("sleep 1; am start -n {包名}/.LaunchActivity");
            PrintWriter.flush();
            PrintWriter.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (process != null) {
                process.destroy();
            }
        }
    }

这样就OK了，可以去试试