With FTP protocol you cannot change listing command.
Though upgrading to 5.0.7 beta may help as it supports MLSD/MLST commands.

martin wrote:

You have probably selected SFTP protocol, so the option is disabled. But WinSCP falled back to old SCP protocol, when connecting, because it was not able to setup SFTP. Select SCP protocol explicitly.

The problem is the server can only be connected by FTP protocol, so I　cannot use SCP protocol, otherwise I can change the listing command. Do you have any other solutions to solve it?

You have probably selected SFTP protocol, so the option is disabled. But WinSCP falled back to old SCP protocol, when connecting, because it was not able to setup SFTP. Select SCP protocol explicitly.

When I try to connect to the server by FTP protocol, it shown this error. I think there must be some problem with listing files, so I want to change the list command. However, I found the option is disabled. Does anybody know how to solve this?