The invention provides a high-strength steel powder for 3D printing in a low-temperature service environment and a preparation technology of the high-strength stainless steel powder for 3D printing inthe low-temperature service environment and belongs to the technical field of metal materials for additive manufacturing. The high-strength stainless steel powder for 3D printing in the low-temperature service environment comprises, by weight, not larger than 0.02% of C, not larger than 0.5% of Si, not larger than 0.5% of Mn, not larger than 0.01% of P, not larger than 0.003% of S, 10.0-12.5% ofCr, 7.5-9.5% of Ni, 2.5-3.5% of Mo, 0.05%-0.15% of V, 4.0%-6.0% of Co, not larger than 0.015% of O, not larger than 0.010% of N and the balance Fe and inevitable impurities. The manufacturing technology of the high-strength stainless steel powder for 3D printing in the low-temperature service environment comprises the steps of preparation of master alloy, plasma rotating electrode powder process and powder screening and collection. The high-strength stainless steel powder for 3D printing in the low-temperature service environment has the advantages that after SLM additive manufacturing and matched heat treatment, a standard component made of the powder has quite excellent comprehensive mechanical properties, especially the low-temperature toughness; the high-strength stainless steel powderfor 3D printing in the low-temperature service environment can be directly used as a powder consumable of a high-performance complicated precise part for 3D printing in low temperature and aerospaceengineering fields and can also be popularized to the medical field, the ocean engineering field and other relevant fields, and the market prospect is broad.