Broadcast is an important link in mobile ad hoc wireless networks (MANETs). In order to improve broadcast coverage, reduce forwarding probability and broadcast collision, a dynamic space-covered broadcast algorithm based on neighbor-degree in MANETs is proposed. The concepts of neighbor-degree, available-angel and available-distance are introduced. The neighbor-degree is used to generate the initial forwarding probability of a node. Based on the available-angle and available-distance, the node weight is proposed to calculate the final forwarding probability, thereby realizing the dynamic selection of forwarding node and reflecting the dynamic space-covered of node. The forwarding strategy is proposed to reduce broadcast collision. Simulation results show that, compared with dynamic probability broadcast and node location based space-covered broadcast, proposed broadcast algorithm reduces the broadcast collision, improves the broadcast coverage, and reduces the forwarding probability when the number of nodes is large.