The invention belongs to vehicle electronic information systems, and particularly relates to a vehicle bus debugging system based on multi-mode signal conversion. According to the technical scheme, a data debugging module of a smart mobile terminal sets bus types and bus parameters for a multi-mode signal converter, the multi-mode signal converter is switched to be the corresponding bus type, collects bus data according to the set bus parameters and sends the bus data to the smart mobile terminal through a signal synchronous adapter, and the data debugging module of the smart mobile terminal samples the data, analyzes the sampling result and displays the sampling result in real time. Compared with the prior art, the system is good in adaptability, expandability and portability, capable of bringing convenience to out-field tests and low in cost.