The utility model relates to a drop indication type lightning protection gap which comprises a gap high-voltage electrode, a gap grounding electrode, a drop-indicating rod, a fuse wire, a connecting hardware fitting, a fixing part and other accessories and is designed for the frequently happened lightning stroke discharge accidents of a power transmission line. A lightning stroke discharge channel is formed between the gap high-voltage electrode and the gap grounding electrode to cause lightning stroke to flash over along the gap and to shift and lead power-frequency arc root to leave an insulator end part, so that an insulator and the power transmission line can be protected from damage, the success of reclosure is ensured, the lightning stroke flashover becomes a transient fault, and the normal power supply of an electric network is guaranteed. When a lightning stroke discharge accident occurs on the lightning protection gap, one end of the drop indicating rod installed on the gap high-voltage electrode or the gap grounding electrode drops off to indicate the occurrence of the lightning stroke discharge, so that the monitoring on conditions of the lightning stroke discharge on the line can be performed. The drop indication type lightning protection gap not only can effectively solve the problem of the lightning stroke discharge of the power transmission line and can accurately indicate whether the lightning stroke discharge occurs or not at the same time so as to provide powerful data for analysis of the lightning stroke discharge on the power transmission line.