Tight reservoir usually has low permeability, it is difficult to establish effective displacement using horizontal well during water flooding for a long time, so it faces the problem of low production and low oil recovery. In order to improve oil recovery and oil production velocity, a new development mode called transformation development was first proposed in Y284 area of Changqing Oilfield in 2016. The transformation development includes three stages: horizontal well energy replenishment before fracturing, energy replenishment during fracturing and energy recovery after fracturing. However, after the transformation development field test, the daily oil production of some horizontal wells is less than 10 tons. On the one hand, it is affected by inadequate fracturing scale and on the other hand, it is affected by injected fluid flowing into non-target areas such as fractures or large pores during energy replenishment before fracturing. In order to improve the success rate of transformation development test and enhance the fracture-controlled reserves of horizontal wells, this paper carried out parameter optimization study for different stages during transformation development based on methods of material balance method, field statistics method and numerical simulation method. Through these methods, we establish the change equation between injected fluid volume and reservoir pressure at the first stage, define the reasonable fracture-placement position and fracturing parameters at the second stage, and determine the reasonable well closed time at the third stage. The research results show that: at the first stage the reasonable pressure maintenance level is 100%; at the second stage the reasonable sand content of per 100 m is 300–400 m3/100m, the fracturing fluid volume injecting to the reservoir is 3000 m3/100m, and the flow rate of hydraulic fracturing is 8.0 m3/min; at the third stage the reasonable well closed time is 40–60 days. Applying the research results, the oil production rate of one horizontal well in Y284 test area increases from 3.2 t/d to 11.7 t/d, and it remains stable for more than 2 years, which improves the utilization of horizontal well reserves effectively.