The invention discloses a rail local defect vehicle-mounting detection method merging with vehicle speed information and front and rear axle box acceleration information, which belongs to the traffic information security technology. The method comprises the following steps of: collecting the vehicle speed information and the front and rear axle box vertical vibration acceleration information of at least one vibration acceleration sensor at one position by a collector, and then merging the speed information with the front and rear axle box vertical vibration acceleration information, extracting the features of the merged information to obtain a time frequency energy distribution function of the vibration acceleration, then finding a displacement coordinate position corresponding to the time frequency energy distribution function peak value, and finally analyzing the acceleration signal at the position of a rotating cycle of a wheel in a shaft space by the method. With the method, the impact feature of the rail local defects can be detected, the line modification is free, and a detection system is simple. Compared with the prior art, the method has high reliability, low cost, fewer channels, a simple system, high anti-interference performance, a wider application space and a higher application value.