Abstract Coprime array can provide high degrees of freedom by using difference–sum co‐array under the same physical sensors, and can estimate the source under uncertain conditions. A special coprime array structure is proposed in this paper. Its difference–sum co‐array can improve the degrees of freedom. Finally, the proposed array structure estimation is used for direction‐of‐arrival. Simulation results and analysis show that the proposed array structure can effectively improve the accuracy of direction‐of‐arrival estimation. Under the same signal‐to‐noise ratio and snapshot number, it has lower root mean square error and higher estimation accuracy than other methods.