The invention discloses a circulation-type automatic-cleaning pH measurement control device and method. The device comprises a pH value measurement washer, a signal matcher and a main control computer. The output end of a pH electrode is connected with the main control computer through the signal matcher; and an ultrasonic electrical signal of the main control computer is input to an ultrasonic transducer through a cable. The method comprises a cleaning step: an embedded computer periodically controls an ultrasonic signal generator to start so as to carry out cleaning on the pH electrode or controls the ultrasonic signal generator to start to carry out cleaning on the pH electrode based on voltage signals sent by the pH electrode. The problems of measurement data interruption in the cleaning process, no PID control function, unsatisfactory cleaning effect by adopting an air static pressure method, complex structure and many faults by adopting the cleaning method of a brush cooperating with cleaning fluid, damage to detected solution due to the need of adding chemical cleaning fluid in the cleaning process, and damage to the electrode due to exposure of the electrode in the air easily caused by cutoff of the detected solution and the like are solved.