In view of present situation and demand, this article introduces one type of testing method and system of muzzle velocity test technology of burst of high firing rate cannon. This method adopts data colleting device to replace timing device. Data colleting device directly collects cartridge-shape analog signal output by sky screen target and measures the flying time of each projectile going through two targets. The flying speed of each projectile can be calculated on the basis of the distance between two targets and flying time of each projectile. This method realizes the muzzle test of burst of cannon under the conditions such as high firing rate, long burst of fire and multi-target. The multiple-verification checked by high firing-rate small caliber cannon demonstrates that this test method can satisfy the test requirements of the muzzle velocity of high firing-rate burst, integrates muzzle velocity, vertical target dispersion with test items, reduces the ammunition consumption of test and improves the working efficiency.