The invention discloses a compressive stress test device for a pipeline floor drain system and a construction method of the pipeline floor drain system. The test device comprises a floor drain, a sealing part and a pressing assembly, wherein the sealing part is used for sealing an opening at one end, close to a pipeline, of the floor drain; the pressing assembly is detachably connected with the floor drain and comprises a pressing part; and when a compressive stress test of the pipeline floor drain system is carried out, the pressing part is used for applying the sealing pressure on the sealing part so as to enable the sealing part to seal tightly the opening at one end, close to the pipeline, of the floor drain. The construction method comprises the steps of installing the pipeline; welding the floor drain to one end of the pipeline; plugging the floor drain, and performing the pressure test of the pipeline floor drain system; and completing the pressure test and removing the pluggingof the floor drain. The test device and the construction method have the advantages of being safe, reliable, time-saving, cost-saving in materials and the like.