NOVELTY - Constructing micro-ecological system comprises constructing micro-ecological pool provided with iron pool frame for lifting water in the sand, setting a drainage system in the micro-ecological pool, collecting human excrement and fermenting, loading the fermented excrement into a earthworm culture plastic bubble film box and culturing earthworm, culturing maggot, adding earthworm and maggot into the micro-ecological pool, introducing loach, eel, tortoise, and Procambarus clarkia, and culturing.    USE - The method is useful for constructing micro-ecological system (claimed).    ADVANTAGE - The method ensures the utilization of domestic waste, ensures the culturing of maggot, earthworm, aquatic animal, and aquatic vegetable, turns biological waste into environmentally food people, achieves natural water body eutrophication. The micro-ecological system has stable price.    DETAILED DESCRIPTION - Constructing micro-ecological system comprises (i) constructing micro-ecological pool of pool depth 0.4-0.6 m and pool bottom of 1/8-3/8 with 15-20 cm high mud bar stack, and is provided with iron pool frame for lifting water in the sand; (ii) setting a drainage system in the micro-ecological pool and controlling the water depth of 12-14 cm in the micro-ecological pool; (iii) collecting human excrement and fermenting; (iv) loading the fermented excrement into a earthworm culture plastic bubble film box, where the difference between the earthworm culture plastic bubble film box from the top is 8-12 cm, adding 1-3 cm water, inoculating adult earthworms with endless belt, placing on north balcony, placing on flower shelf and roof of the outer window, and placing on glass box, performing heat preservation, and every day feeding the household waste to the earthworm; (v) adding spring, summer and autumn fermented excrement into a maggot culture plastic bubble film box, where the difference between the maggot culture plastic bubble film box from the top is 8-12 cm, inoculating maggot eggs, placing on the north balcony, flower shelf and roof of the outer window, harvesting once for every four days, feeding maggot eggs and re-culturing; (vi) adding earthworm and maggot into the micro-ecological pool; (vii) placing on the sand bar at spring, summer and autumn season of bamboo leaves, and placing in autumn and winter seasons of watercress; (viii) introducing loach 20/cm2, eel 4/m2, tortoise 4/m2, and Procambarus clarkia 1 pair/10 m2; and (iv) collecting the turtle eggs from the plastic box in summer, dredging loach, eel and tortoise in winter, removing loach, where the eel grows 1-2 fold per 3/m2 and the eel is 10 cm, removing tortoise from the plastic box, and placing in water in winter.