The utility model discloses a high-temperature instrument constant-power ribbon heater for environmental protection monitoring. The problem that an existing ribbon heater is unstable in heat productivity is solved. The shearing cannot be performed according to the actual use length; the overall strength is low; better use by people is inconvenient; the service life is shortened; it comprises a metal mesh grid, the inner side of the metal mesh grid is glued with a sheath; the inner side of the sheath is glued with a first glass fiber sleeve; a heating wire is mounted on the inner side of the first glass fiber sleeve; the utility model is advantageous in that the structure is simple, the heating value of the ribbon heater per unit length is constant; the longer the used ribbon heater is; thelarger the output total power is; the ribbon heater can be cut at will according to the actual required length on site; in addition, the ribbon heater has flexibility and can be conveniently laid close to the surface of a pipeline, the braid layer on the outer layer of the ribbon heater not only plays a role in heat transfer and heat dissipation and improves the overall strength of the ribbon heater, but also can be used for anti-static safe grounding, and has the characteristics of high maintenance temperature, long one-way use length and long service life.