Disclosed is an overcurrent simulation method when a nail penetrates a secondary battery and a recording medium storing the program. The overcurrent simulation method according to the present disclosure constructs a safety device and a secondary battery equivalent circuit, and produces a nail penetration effect by changing a resistance value. In this instance, various current simulations may be obtained by changing a first metal sheet and a second metal sheet included in the safety device, and a resistance value limiting an overcurrent may be calculated.