X-ray pulsar-based navigation is a revolutionary technology which is capable of providing the required navigation information in the solar system.Performing as an important pulsar-based navigation technique,the Significance Enhancement of Pulse-profile with Orbit-dynamics(SEPO)can estimate orbital elements by using the distortion of pulse profile.Based on the SEPO technique,we propose a grouping bi-chi-squared technique and adopt the observations of Rossi X-ray Timing Explorer(RXTE)to carry out experimental verification.The pulsar timing is refined to determine spin parameters of the Crab pulsar(PSR B0531+21)during the observation periods,and a short-term dynamic model for RXTE satellite is established by considering the effects of diverse perturbations.Experimental results suggest that the position and velocity errors are 16.3 km(3σ)and 13.3 m/s(3σ)with two adjacent observations split by one day(exposure time of 1.5 ks),outperforming those of the POLAR experiment whose results are 19.2 km(3σ)and 432 m/s(3σ).The approach provided is particularly applicable to the estimation of orbital elements via using high-flux observations.