Currently, research on the intrinsically safe features of intrinsically safe circuits mostly relies on the IEC spark experimental device as the experimental platform. The research only analyzes the discharge features of a single capacitor or inductance circuit. There are problems such as poor applicability and high requirements for experimental conditions. There is a lack of research on the intrinsically safe features of hybrid intrinsically safe circuits. To solve this problem, based on GB/T 3836.4-2010 Explosive Atmospheres - Part 4: Equipment Protected by Intrinsic safety Type 'i', a short circuit transient energy experiment is carried out with the hybrid circuit under the cutoff type protection mode as the experimental object. By analyzing the release process of short circuit transient energy, a mathematical model of short circuit transient energy is established. The paper analyzes the effects of capacitance, inductance, power supply voltage, and protection time on short circuit transient energy in the equivalent mathematical model. The Matlab simulation results show that as the capacitance and inductance increase, the transient energy of the short circuit will gradually increase and eventually approach a stable value. Increasing the power supply voltage will significantly increase the short circuit transient energy. Shortening the action protection time can effectively reduce transient energy. But its effect is only significant when the protection time is less than the critical time. An intrinsically safe power supply is developed based on a mathematical model of short circuit transient energy. The short circuit experiments are conducted. The experimental results show that the waveform of short circuit current and voltage is basically consistent with theoretical analysis. The transient energy of short circuit is 33.22 μJ, which meets intrinsic safety requirements and can provide a reference for the design of intrinsically safe power supplies.