Abstract Power splitter is one of the fundamental elements in photonic integrated circuit. Among various power splitter structures, nano-pixel-based ones have attracted attention because of the flexible design capability. As there is no rigid design rule in nano-pixel layout, inverse design algorithms are employed to realize the target function. Machine-learning needs in general criteria during design process, and one typical criterial is the device excess loss. For the designing of 1×N power splitter, it is not sufficient in consideration of power valance among N output-ports. In this study, we propose an electric field profile evaluation method which evaluate the total field profile at the device facet in addition to the excess loss. We exploit the criteria including above method to design 1 × 4 power splitter. As a result, the simulated results show all four 0th order modes and the output power are 24.490%, 24.494% with excess loss of 0.1 dB..