The utility model relates to an automatic speed change controller, which is composed of a chassis, array photoresistors, a fanning strip, a throttle pointer, etc. The array photoresistors are distributed on the chassis at inside and outside, the fanning strip is arranged on the array photoresistor, and the throttle pointer is arranged above the fanning strip. The automatic speed change controller can improve the combination property of the complete motorcycle to make the motorcycle achieve the optimal running effect; a motorcycle engine always keeps the optimum load operating condition, and the loss of the engine power is reduced up to the hilt, and the service life of the engine is extended. Moreover, the structure is simple, and the operation is reliable.