Hydraulic fracturing can greatly improve the production capacity of well, which is one of the key technologies for efficient development of tight oil and gas resources. If the fracturing fluid can not flow back in time after fracturing operation, fracturing fluid entering deep reservoir will cause reservoir damage. The previous research mainly focuses on improving the fracturing technology to improve stimulation effect, and the research on backflow of fracturing fluid is less. Flow back of fracturing fluid is currently focus on qualitative analysis, there are few quantitative calculations. To address this problem, this paper takes the tight gas fractured horizontal well in Sichuan Basin of China as the research object, flowback time of gas wells is affected by geological parameters, production testing parameters of flowback period and fracturing parameters. Analysis of simple correlation is hard to quantify the relationship between flowback time and affected parameters. Pearson Correlation Coefficient and grey correlation analysis are used to statistically analyze 15 geological and engineering parameters, such as pressure coefficient and total liquid volume. Total liquid volume, permeability, water saturation, horizontal section length and pressure coefficient, are the key factors affecting the flowback time of gas wells. The research results of this work can provide some guidance for fracturing fluid backflow parameter optimization.