The calculation of arch dam stress by multi-arch beam method can be realized by vector and matrix calculation.Using object-oriented computer language， data objects of vectors and matrices are constructed， and complex vector and matrix operations can be abstracted into simple numerical calculations through operator overloading.The data structure simulating the node grid of arch and beam is constructed，and the related calculation of arch and beam can be conveniently simulated by using the linked list traversal technology.Through vector and matrix operations，a reaction force parameter matrix can be formed to quickly solve or adjust the internal force of arch crown or load sharing between arch and beam.Through the above object-oriented programming techniques，the difficulty of programming can be greatly reduced.