The invention discloses a structure for shoring of a foundation trench and a construction method. The foundation trench needing shoring construction is composed of a middle foundation trench body and two side foundation trench bodies on the two sides of the middle foundation trench body. The construction method comprises the following steps that firstly, earthwork of the foundation trench is excavated to a foundation bottom elevation position of the middle foundation trench body; secondly, foundation piles of the middle foundation trench body and support piles of the two side foundation trench bodies on the periphery of the middle foundation trench body are constructed; thirdly, structural bottom plates of the middle foundation trench body are constructed at the foundation bottom elevation position of the middle foundation trench body; fourthly, earthwork of the two side foundation trench bodies is excavated to a position where a counter-pulled anchor with prestress is arranged, and a counter-pulled anchor with prestress is constructed between the two side foundation trench bodies at the position; and fifthly, the fourth step is executed repeatedly, the earthwork of the two side foundation trench bodies is excavated from top to bottom, counter-pulled anchors with prestress are sequentially constructed until foundation bottom elevation positions of the two side foundation trench bodies are reached.