Cascade control is a one of control loop that use in the industry which is good in engineering. The advantages of the cascade control are reducing effective magnitude of time-lag and disturbances. On the other hand, the disadvantages of cascade control are the complicated of the system and unstable process if the controller not good enough. The step we use to control the plant with cascade control follow to each step; Step one, set up the inner loop and outer loop to manual then step the CO of outer loop to get the respond of inner loop. Then, approximate transfer function of the plant and tuning the controller of inner loop. Step two, set up the inner loop to auto and outer loop to manual to get the respond of outer loop. Then, approximate transfer function of the plant and tuning the controller of outer loop. Step three, set up the inner loop and outer loop to auto to get the respond of overall cascade control loop.