In order to solve the general problems of information overlap, low energy utilization rate and network transmission security in routing protocols of wireless sensor networks, a scheme of energy-efficient and security-high routing for wireless sensor networks (EEASHR) based on improved Kruskal algorithms is proposed in this paper. The proposed scheme takes the energy size required for transmission and the value of reliability between nodes and nodes as the edges value of graph, then uses improved Kruskal algorithm to generate the minimum spanning tree (MST) in sink node, in other words, the optimal route path. The simulation in NS2 shows that the proposed algorithm improves network energy efficiency, reduces the node packet loss rate and prolongs the life cycle of wireless sensor networks.