The invention discloses a gas-liquid interface speed measuring device with improved measurement precision, which comprises an oscilloscope, more than two gas-liquid interface monitors and more than two signal amplifiers, wherein each gas-liquid interface monitor comprises a laser emitter and an electro-optical signal converter arranged on a light path of the laser emitter; the light paths of all the laser emitters are parallel; the electro-optical signal converters are electrically connected with the input ends of the corresponding signal amplifiers respectively; and the output ends of the signal amplifiers are electrically connected with the oscilloscope. The invention has reasonable structure, convenient and rapid measurement and high measurement precision and can eliminate the shooting error of a high-speed shooting method in the prior art.