Asia Communications and Photonics Conference (ACP) has been the world's most recognized and largest academic conference in optical communications, optoelectronics and related fields in Asia. Since 2001, it has been held for 17 consecutive sessions. ACP 2018 was held in Hangzhou on October 26-29, 2018. The paper authored by Peng Zhao "High-dimensional linear operation for phase-coherent spatial modes" won the Best Paper Award, which selects only 4 award-winning papers from a total of 576 academic papers accepted by the conference. The manipulation of high-dimensional optical states has always been an important research direction in the field of information optoelectronics. This paper proposes a new scheme of high-dimensional photon linear transformation based on spatial coherent states, and experimentally implements 24-dimensional arbitrary matrix transformation. The matrix dimension is 4 times that of the previous record. High-dimensional photon linear transformation has a wide range of important applications in the fields of optical communication, optical computing and quantum computing. This paper provides a new way for breakthroughs in related fields.