Disclosed are a parallel start control method and system for a hybrid electric vehicle, and a hybrid electric vehicle. The parallel start control method for a hybrid electric vehicle includes: acquiring current working conditions of a clutch and a gearbox of the hybrid electric vehicle, an engine request torque of the hybrid electric vehicle and a start mode of the hybrid electric vehicle; judging whether the hybrid electric vehicle meets an over-heat protection condition according to the current working conditions of the clutch and the gearbox, and determining a start basic torque according to a judging result and the engine request torque; determining a start clutch request torque based on the start basic torque according to the start mode of the hybrid electric vehicle; and conducting start control on the clutch according to the start clutch request torque. The parallel start control method for the hybrid electric vehicle is capable of improving the start security, responsiveness and power performance of the hybrid electric vehicle.