Device time synchronization control method in wireless mesh network, comprising: pulse converter converts input AC into periodic pulse signal; controller sends time setting instruction to adjacent node device at preset time; adjacent node device updates device time according to preset algorithm when periodic signal is on rising edge or falling edge, take updated device time as setting time and forward to other adjacent node devices before arrival of next rising edge or falling edge; other adjacent devices update own device time when periodic signal is on rising edge or falling edge; after all node devices finish updating device time, controller sends control commands, and all node devices execute synchronously upon arrival of execution time. Node devices update own time according to pulse signal changes, realizing clock synchronization and synchronization control over node devices by uniform execution time.