The invention discloses a blind watch and a time correction method and system thereof. The charging circuit unit charges the rechargeable battery, the rechargeable battery and the power management unit supply power to each unit circuit, and the microprocessor unit with voice output is respectively connected with the key input unit, the piezoelectric ceramic amplification and boost drive circuit, the transmitting and receiving switch, and the ultrasonic receiving, filtering, amplification and shaping unit. The transceiving switch is connected with the piezoelectric ceramic chip, and the microprocessor unit with voice output controls the transceiving switch to be connected with the piezoelectric ceramic amplifying and boosting driving circuit or the ultrasonic receiving, filtering, amplifying and shaping unit.

The invention does not need to set the time manually, and automatically checks the time when charging, which is convenient to operate, low in cost and high in accuracy.