不行，微信号是微信的唯一ID，只能修改一次。
没有修改过微信号的，可以通过下面步骤修改：
一、在手机桌面上找到“微信”图标。
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https://iknow-pic.cdn.bcebos.com/d009b3de9c82d158e6de1df58d0a19d8bc3e4211"/>
二、点击微信进入后，点击右下角的“我”，然后再找到“设置”一栏。
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三、点击设置进入后，选择“帐号与安全”一栏。
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https://iknow-pic.cdn.bcebos.com/c75c10385343fbf25774e267bd7eca8065388f1e"/>
四、点击帐号与安全进入后，找到“微信号”一栏。
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https://iknow-pic.cdn.bcebos.com/562c11dfa9ec8a13cf6313a4fa03918fa0ecc07d"/>
五、点击微信号进入后，将系统随机分配的微信号删除，填入自己想要的微信号即可。
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https://iknow-pic.cdn.bcebos.com/023b5bb5c9ea15ceec96a44dbb003af33a87b27e"/>