The invention discloses a multiple-serial-port 
bus system based on AT91M40800, which includes a micro-controller unit, an 
Ethernet interface unit, a CANBUS interface, a RS-485 interface unit, and an 
infrared remote interface unit. The 
Ethernet interface unit and CANBUS interface unit are connected with the micro-controller unit through a parallel 
bus, the RS-485 interface unit connected with the micro-controller unit through a serial 
bus, and the 
infrared remote interface unit connected with the micro-controller unit through parallel I / O interface. A third-party device is connected with the current inspection and monitor network through the multi-port 
system, which keeps clear of varied site networks of 
network interface type and protocol type, thus effectively solving the difficulty that the third-party device can not find access to the present network due to undisclosed techniques, and also the problems of the maintenance, upgrading, supplementation, and selection of inspection and monitor 
system in 
coal mines. The invention can avoid repeated purchase of system and equipment, lower investment and repair expense, and improve inspection and monitor system in 
coal mines. Therefore, the invention is particularly suitable for 
network connection equipment of inspection and monitor system in 
coal mines.