The invention relates to the technical field of automobile key circuits, and specifically discloses a car key circuit with short circuit protection. The car key circuit is provided with a power supply. The power supply is provided with a power supply positive terminal and a power supply negative terminal, and is also provided with a key connected with the power supply positive terminal. The powersupply negative terminal is connected with a first ground. The power supply is also provided with a first voltage-dividing circuit connected between the key and the ground, an on-off control circuit connected between the power supply positive terminal and a second ground, and a protection circuit connected between the first voltage-dividing circuit, the on-off control circuit and the second ground. According to the car key circuit provided by the invention, the voltage-dividing circuit and the protection circuit are added in the key circuit. When a short circuit fault occurs in the key circuit, the key protection circuit protects the circuit from damage, and when the fault is removed, the circuit can automatically return to normal. The car key circuit is suitable for car body parts such asemergency flasher control keys requiring high reliability, and has the advantages of few added components and low cost, and the circuit is easy to build.