Abstract: When traditional wireless sensor network based on single sink node is applied in coal mine monitoring system, the sensors far away from tunnel crossing cannot transmit monitoring data to sink nodes in the tunnel crossing real timely and exactly. In order to solve above problem, a routing protocol for wireless sensor network based on multi sink nodes was proposed which was suitable for long strip structure of coal mine tunnel. The protocol introduces wireless sensor network structure based on multi sink nodes and unequal clustering thought, and adopts a power control algorithm based on multi sink nodes and an unequal clustering algorithm to optimize the optimal communication radius, transmit power, cluster head selection and calculation method of unequal radius of each sink node. The simulation results show that the protocol has advantages in connectivity, delay and network lifetime, and can reduce the whole network energy consumption effectively and prolong network survival time.