The distribution of Hα spectral lineshape has been derived from the surface of limiter in HT-6M torkamak, with Optical System Mutichannel. The energy distribution of hydrogen atoms has been directly derived from the distribution of Hα lineshape, Main molecular processes at plasma edge have been discussed. Plasma ion temperature has been obtained from fitting remote wing of the distrubution of Hα lineshape with Gaussian function.