Since the first detection of gravitational wave from binary black hole merger (GW150914) by LIGO, the pursuit of the Gravitational Wave Electromagnetic counterpart (GWEM) became important and urgent. However, the existing gamma-ray monitors were insufficient to capture the transient GWEM in gamma-rays which occurs randomly all over the sky, because either the Field of View (FOV) is constrained by the Earth or the sensitivity is inadequate.

In response to the GWEM science opportunity, GECAM was proposed in the March of 2016 to provide a 100% all-sky monitoring in X-ray and soft gamma-ray band based on the constellation design of two identical microsatellites. Promoted by the first detection of GW EM (especially the GRB 170871A) of binary neutron star merger (GW170817), GECAM was selected and funded by the Chinese Academy of Sciences (CAS) in July 2018.