In this work, we realized the formation of La(Fe, Si)13Hy by making use of the released hydrogen atoms from the solid hydrides. Under the annealing process, NaZn13-type magnetocaloric phase absorbed the released hydrogen atoms from the solid hydride YH2, which can be further promoted through pre-milling the mixture of YH2 with carbon. The highest increase of Curie temperature is about 123 K when the compact mixture of LaFe11.65Si1.35 with 15 wt.% YH2-C was annealed at 813 K. The magnetic hysteresis loss was also largely suppressed with a slight decrease of magnetic entropy change. This solid method would exhibit the merits of process and plate shaping under a certain pressure.