The invention relates to the technical field of building construction, in particular to a high pier continuous beam side span cast-in-place section and closure section integrated construction system and construction method, the construction method comprises the following steps of: construction preparation; construction monitoring calculation analysis; cantilever construction to the closure sectionand bridge approach construction; basket forward movement and basket platform reconstruction; pre-pressing; side span cast-in-place section construction; side span cast-in-place section construction;side span closure section construction; side span closure section tensioning; and lifting platform system dismantling. Compared with a prior method, the method effectively solves the problem of highpier support erection, avoids a large number of support erection construction, adopts the stress of the hanging system of the hanging basket, has simple construction technology, reduces the use amountof materials, reduces the use of large-scale hoisting equipment, has the obvious advantages of cost saving, construction period saving, better technical economy and the like aiming at the work of possibly prior support treatment and the like, avoids the prior construction support erection, avoids the work of a large number of basic treatment and the like, and has obvious construction period saving.