From a technical and theoretical perspective, creating new human variants suitable for medical research through genetic engineering is a highly controversial and problematic idea, and is currently strictly prohibited and restricted worldwide. First, this involves serious ethical issues. Changing human germ cell genes will have unpredictable long-term effects on future generations, impacting the basic ethical bottom line of mankind, and may trigger concerns about a series of violations of human dignity and fairness principles such as "designer babies". Secondly, there are also great challenges in technology. The gene regulatory network is extremely complex. It is almost impossible to fully realize the precise manipulation of genes to create new human variants that meet the needs of specific medical research and are healthy and stable at this stage, and it may also bring uncontrollable health risks and unknown genetic defects. Furthermore, this behavior violates the principle of natural genetic diversity of humans and destroys the natural ecological balance of human genetic resources. In short, based on ethics, technology and the multi-faceted impact on human society, this practice is not allowed and should not be attempted. There are many other legal and ethical ways and methods to advance medical research, such as in vitro models, animal experiments, and genetic research on non-germ cells.