A simultaneous phase shift interferometry was proposed to determine the time delay accurately in the pulse laser pump-probe detecting. The relevant optical system formed by four light interference channels was designed and optimized based on Jones theory. The light intensity distribution of interference pattern associated with the phase lag from these four light interference channels was derived by Jones matrix. The possible errors that exist in the applications were calculated. The theoretical results show that the minimum resolution of the time delay can be achieved to attosecond level for 800nm laser wavelength.