The utility model relates to a secondary cooling water branch. The secondary cooling water branch comprises at least one branch, wherein the configuration of each branch is the same, each branch comprises a branch trunk, and the downstream of each branch trunk is in parallel connection with a middle branch and at least one widthwise cut branch; each middle branch is equipped with a first electromagnetic flowmeter, the downstream of each first electromagnetic flowmeter is equipped with a first pneumatic regulating valve, amended water volume is transmitted to each first pneumatic regulating valve through a first PLC (Programmable Logic Controller) control module by means of analog signals, and each first electromagnetic flowmeter feeds back signals to the first PLC control module; each widthwise cut branch is equipped with a second electromagnetic flowmeter, and the downstream of each second electromagnetic flowmeter is equipped with a second pneumatic regulating valve; amended water volume is transmitted to each second pneumatic regulating valve through a second PLC control module, and each second electromagnetic flowmeter feeds back signals to the second PLC control module. According to the secondary cooling water branch, the water volume of the widthwise cut branches can be accurately controlled and regulated according to process requirements, so that the cooling intensity of the middle part and the edge part of a casting blank can be uniform.