The invention belongs to the field of ceramic material forming and particularly relates to a high-stability hot pressure injection forming system. The high-stability hot pressure injection forming system comprises a constant temperature heater, a heating trough, a mold, slurry and the like. The heating trough is of an interlayer structure. A slurry containing trough is arranged in the heating trough, and the slurry is contained in the slurry containing trough. A heating medium is injected into an interlayer of the heating trough. The constant temperature heater is attached to the periphery of the heating trough. A heating medium liquid level monitoring device is further arranged on one side of the heating trough. The slurry containing trough is sealed through a material storage cover located at the top of the heating trough. The mold is tightly arranged on the upper surface of the material storage cover. One end of a slurry conveying pipe penetrates through the material storage cover to communicate with the mold, and the other end of the slurry conveying pipe extends into the inner bottom end of the heating trough. A through hole lead-in gas path system is further arranged at the upper end of the heating trough. Through the high-stability hot pressure injection forming system, the heating medium liquid level can be monitored at any time, a proper amount of the heating medium is injected as required, and the heating efficiency and process parameter-product performance stability are improved.