Cancer is the second leading cause of mortality worldwide, in which early detection is essential for improving patient outcomes and enabling early treatment. Microfluidic systems can offer promising methods for cancer cell sorting due to their minimal sample requirements, fast processing times, and cell isolation capabilities. However, current microfluidic systems heavily rely on complex techniques, such as magnetic or electric fields and/or size-based channels, constraining the separation efficiency. In this study, a secondary-flow enabled microfluidic chip is designed, which is fabricated by digital light processing (DLP) three-dimensional (3D) printing to achieve high-precision, rapid fabrication of specific microfluidic channels. This 3D printing method enables customizable and cost-effective microfluidic device production. By utilizing secondary flow in the microfluidic chip system, it is technically feasible to separate cancer cells from normal blood cells due to their size difference. A representative application demonstrated in this work is to sort mimicries of red blood cells and circulating tumor cells with a relatively high efficiency. This approach offers a streamlined and scalable alternative for particle separation, providing a robust platform for liquid biopsies in cancer monitoring. Additionally, the proposed approach is expandable to other industrial fields, such as mining, in which precise separation is essential and necessary.