The utility model provides a self-commutation reactive power compensator based on a current source converter. The self-commutation reactive power compensator based on the current source converter is connected with a three-phase DC voltage source and includes a bidirectional three-phase switch connected with the three-phase DC voltage source and an electric reactor connected with the bidirectional three-phase switch in parallel. The self-commutation reactive power compensator based on the current source converter realizes self-commutation through the bidirectional three-phase switch and is realized through the electric reactor connected with the bidirectional three-phase switch in parallel. The self-commutation reactive power compensator based on the current source converter is small in size. And since a large amount of passive components are removed and capacity requirements compared with a semiconductor switch are comparatively low, the cost of the self-commutation reactive power compensator based on the current source converter is reduced. Since the self-commutation reactive power compensator based on the current source converter is comparatively small in size, the self-commutation reactive power compensator based on the current source converter is also especially suitable for occasions with limited space. The self-commutation reactive power compensator based on the current source converter can be used for stabilizing a power transmission system, improving voltage regulation rate and correcting power factors and also for correcting load unbalance at the same time. By using the self-commutation reactive power compensator based on the current source converter, user-side power factors and electric energy quality can be improved, so that line loss can be reduced and electric energy utilization efficiency can be improved.