The present disclosure provides a method for constructing a motion information candidate list, a method and an apparatus for triangle prediction decoding. The method includes: determining a checking order for each of spatial candidate blocks of a current image block; wherein the checking order for the spatial candidate block on top of the current image block is prior to the checking order for the spatial candidate block on the left of the current image block; determining spatial candidate motion information based on the checking order; and constructing a motion information candidate list corresponding to the current image block based on the spatial candidate motion information. The method can reduce coding consumption, and improve coding performance.