The invention discloses a method for laying a temporary road during openly cutting foundation pits, relating to the technical field of design and construction of the foundation pits in underground engineering. The method comprises the steps: transversely dividing an area corresponding to the foundation pit to be constructed into a first area and a second area along municipal roads, and remaining traffic on the municipal road corresponding to the second area; closing the first area, and constructing the first area; erecting a plurality of first-area first reinforced concrete cross-brace and longitudinal joining beams, and pouring road plates on the first-area first reinforced concrete cross-brace and longitudinal joining beams; closing the second area, opening to traffic on the municipal road corresponding to the first area, and constructing the second area; then, cutting the foundation pit on the second area, and setting multiple rows of braces in the foundation pit until the bottom of the foundation pit. The method can improve the safety of the foundation pit and meanwhile can alleviate the traffic pressure on the ground