The invention discloses a subcritical, supercritical pressure, temperature and phase state teaching experiment bench. The subcritical, supercritical pressure, temperature and phase state teaching experiment bench includes an experiment box body, a steam generation cylinder arranged in the experiment box body, a light source generator located at the rear side of rear transparent quartz glass, a heating system arranged in the experiment box body, a cooling system arranged in the experiment box body, a temperature sensor arranged on the steam generation cylinder, a pressure sensor arranged on the steam generation cylinder, a vapor injection valve communicated with the steam generation cylinder, a liquid discharge valve communicated with the steam generation cylinder, and an upper computer which is connected with the light source generator, the heating system, the cooling system, the temperature sensor and the pressure sensor respectively; and the front side end and the rear side end of the steam generation cylinder are provided with front transparent quartz glass and the rear transparent quartz glass respectively in a sealing manner. The subcritical, supercritical pressure, temperature and phase state teaching experiment bench has the advantages of wide testing range, high bearing pressure, simple operation, safety and reliability, and can improve experiment efficiency.