The Fuyu oil reservoir in the Sanzhao area of the northern Songliao Basin is dense and has a small thickness of oil bearing layers. In recent years, effective utilization of the reservoir has been achieved by opening up development test zones and adopting a single well production mode of "horizontal wells + volume fracturing". In response to the problems of large differences in single well production, inconsistent decline patterns, and difficulty in predicting production capacity, this article studies the geological and engineering related influencing factors of single well production and stable production capacity in the experimental area. Based on the Blasingame decline analysis method and boundary control flow, a typical analysis curve is established using the function relationship between pressure integral and its derivative and material balance time. The curve is fitted and analyzed with actual data processed by production regularization. A study is conducted on the production capacity evaluation of fractured horizontal wells in different fracturing scales, reservoir distribution ranges, and production stages. A classification standard for fractured horizontal wells in the Songbei Sanzhao area is established under comprehensive factors such as fracturing transformation scale, flow stage characteristics, and well control reserves evaluation. Development strategies are proposed, and the research results are applicable to the classification of fractured horizontal wells in the Songbei Sanzhao area. The productivity evaluation and development potential research of fractured horizontal wells in the northern region are of great significance.