Abstract: In this paper,a comprehensive study of flare of 14,July 1980 is presented by using the patrol,of H_α,white light,S₂HG observational data obtained at Yunnan observatory,radio data at Beijing observatory and X-ray data from SMM.Compared with EMF (Emerging Magnetive Flux) model,the morphology features of the active region are analysed and the magnetic energy which is released during the flare,the characteristic time of the flare process,the total number of accelerating electrons during the flare eruption and average energy of accelerating electrons are estimated.The results show that:1,EMF model is in good agreement with the observations.2,On the basis of the velocity data and analysis for the site of flare eruption.It seems that the node and nearby region of velocity neutral line and magnetic neutral line (or dark filament) is probably the position of the current sheet.3,The observational results show that the hard X-ray burst is produced by high energy non-thermal electrons accelerated in the current sheet.But solf X-ray burst is produced by hot bremsstrahlung of high-temperature plasma in the flare region.