There is a ROS (single network card) under the same switch, and I have opened PPPOE SERVER on it. This ROS itself uses VRRP+bridge multi dial method to access the Internet. The PPPOE SERVER is built to enable virtual machines on the same computer under the same switch to access the Internet through PPP dial-up. The current problem is that the VRRP PPPOE-out in ROS must specify an AC name to access the Internet normally, and the host system dial-up of that computer must also be specified! Otherwise, it will automatically be dialed to the PPPOE SERVER in ROS. Is there a way to make the PPPOE SERVER in ROS only target those

Draw a diagram or find a way to better explain your issue so that others might be able to help you

PPPoE works directly over ethernet ... so VRRP and routing etc. doesn't affect it. So yes, ISP's and your own PPPoE servers can interfere with each other.

You should separate WAN and LAN on L2 (it seems you don't have it right now, only on L3), VLANs seem a natural solution to your problem (in this case PPPoE domains would be separated by VLANs). This naturally includes your switch (and beyond, at least up to demarcation point between your networks and ISP).

I am a rookie. Can I set up a VLAN in ROS and solve this problem? How should I set it up?

Not only in ROS, also elsewhere. VLANs work between devices, if one uses them but the rest don't then they are either no good or interfere with traffic.

Here kicks in the suggestion by @loloski: show us the physical/logical network topology (which includes ISP gear) so we can suggest you all the necessary changes needed.