Aiming at the problem of continuous acidification of soil in mountainous areas of Southwest China，long-term joint positioning tests were carried out at four test stations in Guiyang，Nanning，Mianyang and Enshi to compare the comprehensive effects of different acid regulation measures on soil improvement and maize yield increase，and further revealed the interaction between measures and maize yield，so as to provide support for the establishment of high and stable yield technical system of maize in mountainous areas of southwest China.The experiment set up five treatments:farmers’ habits (A1，CK)，soil conditioner application(A2)，lime application (A3)，organic fertilizer application(A4) and planting green manure before maize planting(A5).The results showed that:(1)The four acid regulation measures significantly improved the soil acidification，among which A2 and A3 treatments had the best effect，with the pH increased by 0.9 units compared with the control，and for A4 and A5 treatments the pH increased by 0.7 and 0.5，respectively；The soil pH of A1 treatment in 2019 and 2020 decreased by 6.7% and 7.6%，respectively compared with that of the foundation soil sample (2016).But under A2，A3，A4，A5 treatments，the soil pH in 2019 and 2020 increased by 8.0%，6.7%，2.5%，0.0% and 8.1%，7.1%，4.8%，0.3%，respectively，compared with that of the foundation soil sample (2016)；However，compared with A1 treatment，the contents of soil organic matter，alkali hydrolyzable nitrogen，available phosphorus and available potassium in A4 treatment increased by 7.4 g/kg，30.2 mg/kg，11.6 mg/kg and 53.9 mg/kg，respectively，which was significantly higher than those in other treatments.(2)From the average yield in 2016~2020，the A4 treatment had the best yield increasing effect among the four measures，with the yield increasing rate of 11.7%.(3)The A4 treatment increased plant height，ear length，ear diameter，grain number per ear and 1000 grain weight most significantly.(4) The four acid regulation measures increased the dry matter accumulation in each growth stage，and the proportion of dry matter accumulation in six - leaf stage and silking stage were higher than that of the control，among which the accumulation of the A4 treatment was the largest.(5) The LAI and chlorophyll contents of A4 and A5 treatments at each growth stage were higher than those of the control.The increase proportion of grain to leaf ratio of A3 and A4 treatments were higher than that of A2 and A5 treatments.In conclusion，the four acid regulation measures could inhibit the trend of soil acidification，while the application of lime，conditioner and organic fertilizer could also improve soil pH，of which the first two measures had the most significant effect.Compared with other measures，the application of organic fertilizer could not only improve the soil pH and fertilize the soil，but also improve the agronomic properties of maize，optimize the structure of sink and source，promote the accumulation of dry matter，and then increase and stabilize yield.Therefore，from the perspective of acid regulation，soil fertility，increasing and stabilizing yield，the application of organic fertilizer is the most ideal acid regulation measure for acidified farmland in southwest mountainous maize planting area.