Aimed at the technical problem with lost circulation treatment in geological drilling, study has been carried out on polymer crosslinked gel. Utilizing the single factor method, the different additives for crosslinked gel systems has been optimized. With environment-friendly vegetable gum as gelation agent, a kind of delayed crosslinked gel has been prepared by adding crosslinking control agent N1 and crosslinking agent No.1. This gel was successful applied in the field plugging test of Guangxi Uranium exploration hole ZK6-37-1, and the problem of lost return has been resolved. Research results indicate that this gel has controlled cross-linking time(10 to 75min), higher gel strength (≥6 MPa), and has a broad application prospect in solving lost return.