thank for your reply again.
Here are some details.
The vpn is not work at my country.But a organization invent a software that can proxy my traffic.
this is it’s software address:GitHub - v2rayA/v2rayA: A Linux web GUI client of Project V which supports V2Ray, Xray, SS, SSR, Trojan and Pingtunnel 
I use debian 10 as template to create a proxyVM. v2ray only can work at local system.I want v2rayA to proxy other appVM’s traffic, so I use v2rayA to set 0.0.0.0:10808.
and then I create a other appVM that use the proxyVM as network.
Here is a familiar example’s address:Qubes OS学习：：新建一个APPVM作为网关，转发远端SOCK5流量_dieju8330的博客-CSDN博客
he was successful. I try a lot of times.But I was failed.