The utility model discloses a drop type priming device, which is applicable to the percussion type priming perforation operation of oil and gas well oil pipe transmission. The device consists of a drop type initiator and a booster joint, which are mutually independent. The drop type initiator comprises a rod body, a rod tip, a delay firing mechanism and an explosive assembly. The rod body is connected with the rod tip through threads. The delay firing mechanism and the explosive assembly are arranged in the rod body and the rod tip. The booster joint comprises a guide cylinder, a gun body joint and a booster pipe which is arranged in the gun body joint. The guide cylinder is connected with the gun body joint through threads. During the perforation process, the upper end and the lower end of the booster joint are respectively and correspondingly connected with an oil pipe and a perforating gun. When the booster joint descends to an aim layer in a well and the initiator is dropped in place along the oil pipe, a tapered boss which is arranged at the upper end of the gun body joint is positioned in a V-shaped slot which is arranged at the lower end of the rod tip. After certain time delay, the delay firing mechanism forces the explosive assembly to output high-speed jet. After passing through the rod tip and an external wall of the gun body joint, the high-speed jet ignites the booster pipe and then ignites a perforation bullet to finish perforation operation. The utility model is safe and reliable and has a low cost.