The invention relates to a network path delay measurement method and device and a time synchronization system. The method includes: obtaining triggering data; Obtaining a preset state machine information table; Acquiring a state machine from the preset state machine information table according to the trigger data, and generating feedback information according to the state machine; Queuing the feedback information in a task queue to obtain a queuing result, and detecting the queuing result according to preset time to obtain a detection result; And performing state processing on the state machine according to the detection result to obtain a timestamp, and calculating path delay measurement data according to the timestamp. According to the invention, through task timing queue scheduling, states of all state machines in delay measurement are jumped to the interface in a unified manner; and a task timer is started in any timing service queue for timing processing, so that the uncertainty of system call delay is reduced, the execution efficiency of the system is finally improved, and the time precision of path delay measurement and time synchronization is improved.