The invention discloses a temperature and pressure controllable rotary erosion experiment apparatus which comprises a frequency control motor, an inner magnetic assembly, an industrial control computer, a pressure sensor, a temperature sensor, an electrochemical workstation, an upper liquid container, an outer magnetic assembly, a connecting rack, a support cover, a prefilming chamber, an observation window, a transmission center shaft, a lower liquid container, a circulating pump and a filter. The rotary erosion experiment apparatus can simulate working conditions of different temperatures, different pressures and the like in the industrial actual environment for erosion transient characteristic tests. By adopting a magnetic transmission system, the sealing effect of the experiment apparatus is ensured; the temperature, the pressure and the pH value can be simulated according to the industrial actual environment, therefore, erosion critical characteristics obtained in the tests do not need to be subject to similarity theory amendment; and an external by-pass circulating system is additionally arranged, thereby ensuring the balanced distribution of experiment medium temperature fields, and realizing that the working condition environment in the prefilming chamber is identical to the environment in the container. The invention can simulate cases of erosion failure existing in process type industries of petrochemical industry, coal chemical industry, seawater desalination and the like.