We propose and realize a new optical state selection method on a cesium atomic fountain clock by applying a two-laser 3-3\'optical pumping configuration to spin polarize atoms.The atoms are prepared in |F =3,mF =0> clock state with optical pumping directly after being launched up,followed by a pushing beam to push away the atoms remaining in the |F =4> state.With a state selection efficiency exceeding 92％,this optical method can substitute the traditional microwave state selection,and helps to develop a more compact physical package.A Ramsey fringe has been achieved with this optical state selection method,and a contrast of 90％ is obtained with a full width half maximum of 0.92 Hz.The short-term frequency stability of 6.8 × 10-14 (τ/s)-1/2 is acquired.In addition,the number of detected atoms is increased by a factor of 1.7 with the optical state selection.