For the issues of the defects of traditional weighted clustering algorithm (WCA) in Mobile Ad Hoc Networks, a safe and load balanced WCA (SLB-WCA) is proposed. SLB-WCA take nodes stability into consideration of the combination weights computing of nodes, and a "relatively typical node degree" is proposed to substitute the simple node degree factors in traditional WCA. In the meantime, according to the degree of each node, SLB-WCA formulates local cluster size constraints instead of global constraints in traditional algorithm. SLB-WCA can make node weights calculation and cluster size control more reasonably, and make the network load more balanced. Compared with traditional WCA, SLB-WCA has less number of cluster heads, better network coverage, which improves the network lifetime effectively.