The invention discloses a steel-concrete composite beam adopting a suspension template system and capable of partially replacing a plate. The steel-concrete composite beam comprises a plurality of steel beams, wherein each steel beam is arranged on a bridge pier cover beam at the upper end of a bridge pier in parallel, and a plurality of fixed steel cross beams are arranged between each two adjacent steel beams to form a steel beam support structure; a replaceable prefabricated concrete slab is arranged in a negative bending moment region on the upper end face of each steel beam support structure, and is fixedly connected with the steel beams through bolt connection pieces; and a non-negative bending moment region on the upper end face of each steel beam support structure is provided witha cast-in-place concrete slab, and the cast-in-place concrete slab is fixedly connected with the steel beams; the prefabricated concrete slab is detachably and fixedly connected to the cast-in-placeconcrete slab through a cast-in-place section prefabrication end, so that a steel-concrete composite beam structure capable of replacing the concrete slab on the negative bending moment region is formed through setting a combination and splicing structure of the prefabricated concrete slab and the cast-in-place concrete slab. By adopting the steel-concrete composite beam disclosed by the invention, the construction and maintenance efficiency can be effectively improved and the operation cost is reduced.