The progress of new concept small-size satellite atomic clock in Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, is introduced. Base on the pulsed optically pumping (POP) and the orthogonal polarization detection technology, the contrast of the transition signal of atomic clock is improved from 30% in absorption detection to about 100%. The detected result reflects the variation of amplitude and phase of incident light. Therefore, the detection sensitivity and the signal-to-noise ratio are improved effectively, which leads to the improvement of the frequency stability of the atomic clock. Under the same experimental condition, POP atomic clock with orthogonal polarization detection technology has a frequency stability about an order of magnitude higher than the result of POP atomic clock using absorption detection. Above all, when the stabilities of the temperature of physics system, the current of magnetic field, and the intensity of laser are improved by about an order of magnitude, the stability of this atomic clock could reach 1×10-13 for 1s and 1×10-15 for a day, which means that this type of POP atomic clock might become a good substitute of the H-maser.