Focus on the problem of the traditional step-size model used in pedestrian dead reckoning algorithm cannot fully reflect individual differences in the research of indoor positioning. We propose a method to establish database of individual feature of step-size based on satellite ranging and then replace the step-size model. Satellite ranging is applied to calculate the step-size in the outdoor, the corresponding relationship between different speed features and step-size is set up. Then we carry out real-time step-size matching indoors for the step, using improved K-nearest-neighbor(KNN) algorithm and calculate people's current position combined with direction information. The actual test results show that the maximum error distance can be controlled within 4%, and the mean absolute error distance can be controlled within 2%. The positional accuracy has a larger enhancement compared to the traditional step-size model.