The invention discloses an installation and construction method of a mechanical grate type waste incineration boiler. The installation and construction method includes the following specific steps ofconstruction preparation, specifically, unpacking inspection of boiler parts and equipment, retesting and paying off of boiler foundation, and configuration and installation of parallels; and installation and construction method, specifically, preparation and manufacturing of auxiliary tools, installation of boiler internal equipment, installation of rainproof shed, hydrostatic test of boiler, installation of boiler wall, steam tightness test of drying and boiling boiler, and safe trial operation, wherein the auxiliary tools includes a steel frame, a platform escalator, a temporary climbing ladder, an aisle guardrail, a temporary platform, a temporary platform guardrail, a scaffold lifting platform and a simple removable support, and the internal equipment includes a boiler grate, a watercooling system, a drum, a superheater and an economizer. The installation and construction method of the mechanical grate type waste incineration boiler is applicable to installation of the mechanicalgrate type waste incineration boiler with a daily garbage disposal of about 500t / d by a single unit in a domestic garbage power plant, the degree of mechanized construction is improved, the labor intensity is reduced, the project quality is guaranteed, the construction period is shortened, and the productivity and economic benefits are improved.