为解决矩形坯生产过程中出现的铸坯质量问题，通过采用多功能喷嘴测试系统进行测试，对二冷喷嘴的冷态性能测试和喷嘴质量分析，运用有限元模拟的方法进行连铸坯凝固过程温度场计算模拟。结合铸坯低倍分析、二冷喷嘴测试以及计算模拟情况，提出了喷嘴优化及二冷配水调整建议。测试结果表明所应用的4种喷嘴均不同程度存在性能问题，温度场发现足辊段返温较大。通过调整喷嘴、优化连铸二冷水制度后，生产的矩形坯质量问题得到了明显改善。 In order to solve the problems of internal quality and surface quality that tend to occur in the production process of rectangular blanks, a multifunctional nozzle test system independently de-veloped by the laboratory is used to test the cold performance of the secondary cooling nozzle and the nozzle quality analysis; the finite element method is used to carry out the connection calculation and simulation of the temperature field of the slab solidification process. The test results show that the four types of nozzles used have different degrees of performance problems. The simulated temperature field shows that the foot roller section has a large return temperature. Combined with the low-magnification analysis of the cast slab, the test of the secondary cooling nozzle and the calculation simulation, suggestions for nozzle optimization and secondary cooling water distribution adjustment were proposed. After the adjustment, the quality of the rectangular slab was significantly improved.