Abstract: LDV provides a non-intrusive useful tool to measure the local flow velocity within a relatively small measurement volume. Since it was developed in 1969,the dual-scatter or fringe type laser velocimeter have become the universally accepted standard. But it can not easily expanded to a three-component system. The nonorthogonal velocity is measured by LDV,from which the orthogonal three-dimensional components are computed through transformation equation. In this paper,the presented measurement techniques of nonorthogonal velocity with LDV gives useful help for application of LDV.