Northern China is a major production area for off-season vegetables in Chinese solar greenhouse. Usually, greenhouse gas emission flux and coefficient in Chinese solar greenhouse are higher than those in the open field. The reason for this phenomenon is heavy nitrogen (N) fertilization (esp. chemical N and organic manure N) and frequent irrigation during year-round cultivation. A novel substrate cultivation method for vegetable production in Chinese solar greenhouse, called soil-ridged/substrate-embedded cultivation (SSC), was put forward to reduce environmental pollution and increase use efficiency of nutrients. To clarify the characteristics of SSC root-zone greenhouse gas emissions, and the regulation effects of biochar and DMPP addition, five treatments were designed in Chinese solar greenhouse under the same nitrogen application level, including soil-ridge cultivation (SC, as a control), SSC (peat: vermiculite: perlite (v/v = 2:1:1), SSC-B50% (biochar: vermiculite: perlite,v/v = 2:1:1), SSC-B25% (biochar: peat: vermiculite: perlite, v/v = 1:1:1:1), and SSC-DMPP (SSC supplemented with 1% (w/w) DMPP of N fertilizer). Results showed that SSC improved fruit yield of sweet pepper of by 10.99% compared to SC. SSC-B50% and SSC-DMPP significantly improved sweet pepper growth compared to SSC. Moreover, SSC-DMPP increased sweet pepper yield by 10.30% compared to SSC treatment, while SSC-B50% and SSC-B25% treatments lowered the yield by 47.1% and 13.7% separately. Five treatments presented various root-zone temperature features. Also, substrate pH of SC, SSC-B50%, and SSC-B25% is alkaline, while SSC and SSC-DMPP treatments is acidic. Besides, the Global Warming Potential was significantly mitigated in the SSC cultivation compared with the SC. Similarly, the greenhouse gas intensity decreased from 0.074 to 0.038 kg CO2-eq kg− 1 yield. Compared with the SSC treatment, cumulative N2O emissions were significantly reduced in the SSC-DMPP treatment. The greenhouse gas intensity also decreased from 0.038 to 0.033 kg CO2-eq kg− 1 yield. Thus, we concluded that SSC was a promising method characterized with reduced greenhouse gas emissions and increased fruit yield. Application of DMPP in SSC cultivation significantly reduced N2O emissions. We recommend SSC method use in Chinese solar greenhouse with DMPP addition in substrate to optimize greenhouse gas mission.