The invention provides a high-temperature low-pressure long-bag pulse dust remover. The high-temperature low-pressure long-bag pulse dust remover comprises a shell (1), a gas purifying chamber (2), an ash hopper (3), an ash discharging valve (4), a filtering bag (5), a spraying and blowing pipe (6), a compressed air tank (7), a pulse valve (8), a lifting valve (9) and a lifting valve cylinder (10), wherein the gas purifying chamber (2) is arranged on the shell (1); the ash hopper (3) is arranged under the shell (1); the ash discharging valve (4) is arranged under the ash hopper (3); the filtering bag (5) is arranged in the shell (1); the spraying and blowing pipe (6) is arranged above the filtering bag (5); the compressed air tank (7) is arranged at one end of the gas purifying chamber (2); the pulse valve (8) is arranged on the compressed air tank (7); the lifting valve (9) is arranged at the other end of the gas purifying chamber (2). The high-temperature low-pressure long-bag pulse dust remover provided by the invention has the advantages that long-time and high-efficiency operation can be achieved under the condition with high-dust-content flue gas at the temperature below 260-280 DEG C, the dust-collecting efficiency can be stabilized to be more than 99.9%, the positive-pressure form and the negative-pressure form are achieved, and an automatic control device is equipped, so that both the resistance and the time can be fixed, and the whole machine can be maintained under the condition of no stop without influence on production.