Nonuniform random distribution and exhausted energy of sensor nodes may lead to coverage blind spots emerged in wireless sensor networks（WSNs）.Aiming at the problems of coverage blind spots in WSNs

a geometry-based distributed coverage blind spots discovery algorithm is proposed

and it is proved theoretically.The main idea of this algorithm is forming a triangle by sensor node and its two neighbour nodes

calculating circumradius and circumcenter of the triangle and judging existence of coverage blind spots under the guidance of relevant theory of geometric graphics.Simulation results on Matlab platform demonstrate that the algorithm not only can detect coverage blind spots and boundary nodes effectively

but also has a good performance in the energy consumption of sensor nodes.