The invention provides an independent-grouting-opening-free reinforcing steel bar grouting connecting sleeve system and a construction method thereof. The system comprises a plurality of independent-grouting-opening-free reinforcing steel bar grouting connecting sleeves and a reinforcing steel bar grouting connecting sleeve with a grouting opening and grout outlets, or comprises a plurality of independent-grouting-opening-free reinforcing steel bar grouting connecting sleeves and a grouting pipe. The system is characterized in that only the grout outlets A are formed in the side walls of sleeve bodies. Compared with frequently-used reinforcing steel bar grouting connecting sleeves, grouting openings special for the side walls are omitted, and therefore machining cost of the sleeves is reduced, and the potential quality hazard that grout is prone to leaking from the grouting pipe and the grouting openings in the construction process is avoided. In addition, by means of the independent grouting openings, fewer grouting pipes and grout outlet pipes are distributed, the technological requirements for constructors are lowered, and construction efficiency and construction quality are effectively improved.