At present, research on crane hoisting system are generally done in way of electrical system and in way of mechanical system, or done in way of simple link of electrical system and mechanical system, so it's difficult to establish an effective and precise mathematical model. For the problem, an electromechanical coupling mathematical model of crane hoisting system was built based on analyzing of relationships between all component parts of hoisting system of crane. The model avoids to neglect interrelationship between the electrical system model and mechanical system model through introducing electromagnetism torque and elastic coefficient of ropes as variables. Meanwhile, a simulation test was performed for the model with speed regulation method based on vector control and taking position of load movement as control variable. The simulation result showed that the model preferably reflectes work process of hoisting system of crane.