The film-under-gate field emission arrays (FEA) are fabricated on the glass substrates by conventional photolithography, anodic oxidation and stripping method. SnO2 emitters are migrated on the cathode of film-under-gate triode by screen printing. The images of film-under-gate FEA with SnO2 emitters are measured by the optical microscopy and scanning electron microscopy (SEM). The electron trajectory in this triode is simulated by ANSYS. It shows that the SnO2 emitters by screen printing are uniformly distributed on the surface of cathode. The electron beam size gradually becomes small with the increase of anode voltage and gradually becomes large with the increase of gate voltage. The cathode plate and anode plate are made of a 5 inch monochromatic film-under-gate field emission displays (FED) panel and its field emission performance are investigated. It indicates that the FED with SnO2 emitters can achieve full-screen light emission when the gate voltage and anode voltage are 140 V and 2000 V, respectively, at the anode-cathode spacing of 1100 μm. In addition, the maximum anode current of fabricated device can come to 232 μA and the highest luminance is approximately 270 cd/m2. Moreover, the emission current fluctuation is less than 5% for 400 min, which shows that the film-under-gate field emission displays with SnO2 emitters by screen printing have a good field emission characteristics and good application prospects.