The invention discloses a plunger type multifunctional pipeline compensator, which belongs to the technical field of heat distribution pipeline compensation devices. A fixed sealing press cover flange and a reducing connection pipe are adopted. An outer sleeve assembly with an outer sleeve inner bearing platform, a plunger inner pipe framework and a plunger inner pipe is integrally sleeved at one end of a core pipe assembly with a plunger outer pipe framework, a plunger outer pipe, a core pipe convex outer ring and a sealing part A. A steel ball and a sealing part are used for straightening. When one end is extruded and pushed by axial thermal expansion force, the core pipe assembly and the outer sleeve assembly can synchronously, integrally and relatively move in coaxial mode. By means of the structure, stress of pipelines is reduced, sealing performance is enhanced, bearing capacity is improved, the effect of corrosion resistance is provided, and the purpose of large compensation amount and wide application scope can be achieved.