The invention discloses a visualization remote access control system and an access control method therefor. An electronic-control door lock is connected to a digital visualization entrance machine by a communication bus. The digital visualization entrance machine, an IP soft switch device, an application server and a control terminal are connected by an IP network. The digital visualization entrance machine transmits an access request to the control terminal by the IP soft switch device, the digital visualization entrance machine and the control terminal confirm operator identity by a video communication system, then the control terminal transmits the confirmed information to the IP soft switch device, the IP soft switch device transmits an access command to the digital visualization entrance machine, and the digital visualization entrance machine opens the electronic-control door lock. Through the visualization remote access control system and the access control method therefor, maintainers can conveniently and momentarily enter into or get out of a transformer station and work efficiency is improved.