The invention discloses a train docking control method, device and medium. The method includes the following steps that the spacing between a main train and a docking train is obtained in real time, wherein the main train and the docking train drive in the same direction on the same main line, and the main train is the power train of the docking train; whether the spacing is smaller than or equalto a spacing threshold; if yes, a speed change rule is set, wherein the speed change rule refers to the positive correlation between the speed of the docking speed and the spacing; according to the speed change rule, the docking train is controlled to catch up with the main train to dock with the main train. It can be seen that the method can achieve the smooth docking between the two trains whenthe two trains are in drive, the overall transport efficiency is improved, energy consumption is reduced, and the operation cost of the train is reduced. In addition, the invention further discloses the train disengagement control device and medium, and the beneficial effects are as described above.