[en] By applying the turbulent heating pulse on HT-6M tokamak, the improved Ohmic confinement phase (H-mode) is clearly observed. At the plasma edge, both the electron temperature and density profiles become steeper, a more negative radial electric field E_r well is developed, and the poloidal and toroidal flow velocities are substantially enhanced. The experimental results indicate that the edge turbulence suppression in the H-mode is mainly caused by the E_r x B velocity shear decorrelation. Across the L→H transition, the poloidal and toroidal rotations and the radial ion pressure gradient all play significant roles for regulating the E_r profile. But in the H-mode the negative well E_r is dominantly maintained by the poloidal rotation υ_θ, and the time evolution also indicates that before the transition υ_θ plays a key role in inducing the rapid variations of E_r and its shear. Moreover, it is evidenced that the electrostatic turbulence-drive Reynolds stress < V-tilde_rV-tilde_θ> may play a crucial role in creating υ_θ and its shear near the plasma edge