Soil acidification has become one of the main factors restricting the quality of cultivated land in China，affecting the food security of our country，bringing it into dynamic supervision and strengthening the comprehensive research on the trend of change has a long way to go. Based on the topsoil data of main agricultural land in Wenzhou in 2004 and 2019，the change trend of soil pH was studied by means of traditional statistics，geostatistics and grid operation，and its driving factors were analyzed. The results showed that the average soil pH value of main agricultural land in Wenzhou decreased from 6.03 to 5.58 in recent 15 years，decreased by 0.45 units，with an average annual decrease of 0.03 units. The change of soil pH varied with soil parent materials，soil types and land use types，which showed that the pH value of four kinds of soil parent materials all decreased，the descending amplitude was littoral sediments>fluvial and lacustrine sediments>igneous rock weathering material>sedimentary rock weathering material；Among the five soil types，paddy soil，coastal saline soil and red soil decreased significantly，by 0.53，0.49 and 0.42 units，respectively，the skeletal soil decreased by 0.19 units，while the fluvo-aquic soil pH increased 0.20 units on average；In the five land use types，the pH value of tea garden soil decreased by 1.17 units，and that of paddy field soil decreased by 0.61 units，the decline degree of dry land，orchard and woodland was basically the same. The acidic soil area of the main agricultural land in Wenzhou has increased greatly in the past 15 years，and the problem of soil acidification is becoming more and more serious. Soil type，acid deposition，chemical fertilizer and seawater reverse irrigation are the main influence factors of the soil pH value changes of main agricultural land in Wenzhou in recent 15 years.