The utility model discloses a feeding device construction system for an underground pipeline system. The feeding device construction system is special for a feeding device construction method for the underground pipeline system. The feeding device construction system comprises an outer protection pipe (2), a waterproof casing pipe (5), a feeding device (4), a welding device and a grouting device (8), wherein the feeding device (4) is formed by a feeding cable (401) and a feeding connector (402); the lower end of the outer protection pipe (2) is contacted with the outer wall of an underground pipeline (1); the waterproof casing pipe (5) is placed in the outer protection pipe (2), the feeding connector (402) is fixedly arranged at the front end of the waterproof casing pipe (5), and the feeding connector (402) and the outer wall of the underground pipeline (1) are contacted and fixedly connected together finally; and the grouting device (8) is used for adding a protection packing at the position of the feeding connector (402) so as to protect the feeding connector (402). The feeding device construction system has the advantages of being comprehensive in technology, remarkable in effect, high in technical maturity and extremely expectable in immense economic and social benefits and bringing convenience to construction operation.