Signal machine monitoring circuit

The invention relates to a signal machine monitoring circuit comprising a main control circuit, and a monitoring circuit and multiple driving circuits which are connected with the main control circuit through a CAN bus. The main control circuit is used for issuing a light group control instruction. The driving circuits are used for receiving the control instruction and driving corresponding red, yellow and green signal lights to work. The monitoring circuit is used for detecting circuit faults in real time and judging related faults, and independently making a signal machine flash in yellow through driving output signals K1 and K2. Signal machine fault monitoring and independent yellow flash control are realized effectively, there is no need to connect all yellow light outputs of the driving circuits in parallel to the monitoring circuit, and wiring is simple. Moreover, the monitoring circuit needs no components related to alternating-current control, and the circuit is safe and reliable and is of low applica