The γʹ precipitate strengthened cobalt-based alloys are expected to develop into advanced high-temperature structural materials. The microstructure is critical in determining their mechanical properties. This study introduces a high-throughput method to establish the solidification-microstructure relationship for a new CoNi-based single crystal alloy (Co-30Ni-11Al-4W-1Ta-4Ti-5Cr, at%). It involves preforming directionally solidification experiments with discontinuous acceleration growth condition to produce a single specimen solidified under a range of solidification rates. The microstructural evolution in the different regions of the sample was evaluated. The results show that the increased solidification rate refined the dendiritic structures, while promoted the segregation of W、Ta、Ti, leading to the increase of (β+γ′) eutectics fraction and the decrease of (γ+γ′) eutectics fraction in the as cast alloys. By contrast, the microstructure of the heat-treated aloys did not appear to be a strong function of the solidification rate. Whereas with the increasing solidification rate, the homogeneity in solute distribution and the size of γʹ phase were improved in the alloys. Furthermore, by using a high-throughput solidification process to simultaneously fabricate single crystal specimens with different content, the effects of Cr content (0, 1, 5 ,7 at%) on microstructures were also investigated in this work. The results can provide reference of the development of γʹ strengthened CoNi-based superalloys.