This horizontal pressure sterilizer adopts a gravity displacement method to eliminate the cold air in the inner chamber, reducing the content of steam cold air in the inner chamber and making sterilization more reliable. At the same time, during the sterilization process of the equipment, the control system automatically adjusts the inlet and outlet steam based on the indoor temperature. Mainly applicable to hospital supply rooms, operating rooms, pharmaceutical factories, and research unit laboratories, for sterilization treatment of medical and experimental cloth items, surgical instruments, and utensils. The sterilization process is automatically controlled without supervision and is convenient to use. Overpressure protection: The safety valve automatically relieves pressure when the pressure exceeds the working pressure. It has a drying function to achieve the drying effect of sterilized items. Low water level protection device: The water cannot be started before reaching high water level, and it will automatically cut off power for protection when low water level is lacking. Equipped with automatic protection devices for over temperature and over pressure. Safety interlock device: When the door is not tightly closed, steam cannot enter the inner main body and an alarm prompt is given. When the pressure in the sterilization room is greater than 0.027MPa, the door is interlocked and cannot be opened. Overcurrent protection: When the current is overloaded, the power circuit breaker automatically cuts off the power supply. The sterilization room is made of high-quality stainless steel.