According to international or internal standards, the popular term “height of the tower crane” is expressed as the size of the lifting moment. The usual unit (not the standard unit) for lifting torque is: ton meters. Therefore, it is necessary to select the most suitable type of tower crane according to the performance table and the above-mentioned operating conditions. Those who choose to be too small can not meet the construction, and forced use will inevitably bring about danger. If the choice is too large, the economic angle is not optimal.