Based on Taguchi method and uniform design method, the three-dimensional numerical parametrical study of offset strip fins was conducted at low Reynolds number. Taken the single fin assembly as test section, the experimental data for 6 scheme fins were obtained, which have the same tendency with the corresponding simulated data. The difference between them is due to the existence of burrs on fin surface caused by manufacturing technology. According to uniform design, the 11 test schemes with 6 factors and 5 levels were yielded. And by adopting the signal to noise ratio and the contribution ratio originated from Taguchi method, the affecting degree of each geometrical parameter on fin performance was investigated. The sequence of effective factors is fin wavelength, fin height, fin angle, staggered fin wavelength, fin width and fin thickness. According to the signal to noise ratio distribution of each control factor at each level, the optimum model was obtained and confirmed validly by the simulation.