The invention belongs to the technical field of tunnel tunneling, and particularly relates to a Y-shaped tunnel grouting structure and a matched grouting method. The Y-shaped tunnel grouting structure sequentially comprises a rock stratum, a grouting layer and a duct piece layer from a tunnel rock stratum to the inside, wherein grouting holes are formed in the duct piece layer, and the grouting holes are used for grouting outwards. The Y-shaped tunnel grouting structure is reasonable in structural design, two kinds of grout are sprayed out through the Y-shaped grouting holes, the two kinds of grout are well suitable for the top, the side part and the bottom of a tunnel respectively, the grouting effect is good, and the efficiency is high; and the two kinds of grout are sprayed upwards and downwards through the Y-shaped grouting holes respectively, the grout sprayed upwards is the grout mixed by mortar and water glass, the characteristics of high viscosity and short setting time are achieved, the back of a duct piece can be effectively filled, the strength can be rapidly generated, the fixing effect on the duct piece structure is achieved, the duct piece is effectively prevented from floating upwards, the grouting can be carried out by depending on existing equipment, the grouting cost is not increased, the utilization rate of the grout is high, two grouting machines work at the same time, the grouting time is short, the grouting pressure can be monitored in real time, and the grouting quality is guaranteed.