The invention discloses a self energy supply lightning current detection system, which is used for being matched with a lightning rod device for use to realize the defection on relevant parameters of lightning current. The self energy supply lightning current detection system comprises a signal sampling maintaining device, an energy taking device, a single chip control unit, a hardware clock unit and a data storage unit, wherein the signal sampling maintaining device comprises a current sensing unit, a first voltage limiting protection unit and a positive/negative peak value maintaining unit which are connected in sequence, and the energy taking device comprises an energy taking coil, a front end protector, a rectifying and wave-filtering unit, a second voltage limiting protection unit, a voltage stabilizing unit and a DC/DC unit which are connected in sequence. The self energy supply lightning current detection system of the invention can continuously realize the monitoring on whether a transmission line or a building lightning rod suffers with the lightning strike or not, and can accurately record the time, the amplitude value in the occurrence of the lightning strike and the polarity, a special triggering circuit is not needed, and the invention has the characteristics of high precision, simple structure, small size, low cost, high safety and the like.