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We report on a very bright, long-duration gamma-ray burst (GRB), GRB~220426A,observed by \emph{Fermi} satellite. GRB~220426A with total duration of$T_{90}=6$~s is composed with two main pulses and some sub-peaks. The spectralanalysis of this burst with Band function reveals that both the time-integratedand the time-resolved spectra are very narrow with high $\alpha \gtrsim 0.2$and low $\beta\lesssim -3.1$. It is strong reminiscent of GRB~090902B, aspecial GRB with identification of the photospheric emission. Then, we performthe spectral analysis of this burst based on a non-dissipated photosphericemission, which can be well modelled as the multicolor-blackbody with a cutoffpower-law distribution of the thermal temperature. The spectral fittings revealthat the photospheric emission can well describe the radiation spectrum of thisburst. We conclude that this burst would be a second burst in the class ofGRB~090902B observed by \emph{Fermi} satellite. We also discuss the physics ofphotosphere and the origin of the high-energy component in GRB~220426A .

Fermi Observations of GRB 220426A: a burst similar to GRB 090902B