The invention particularly relates to a flat plate display of a suspension square cathode type high angle grid control structure and a manufacturing process thereof. The flat plate display comprises the following components: a sealed vacuum chamber consisting of a cathode glass panel, an anode glass panel and a glass frame; an anode drainage layer, an anode connection layer and an anode covering layer which are arranged on the anode glass panel, and a luminescent layer which is prepared on the anode drainage layer; and an isolator and a getter which are positioned between the anode glass panel and the cathode glass panel. The suspension square cathode type high angle grid control structure comprises a cathode glass panel, a cathode barrier layer, a cathode bottom layer, a cathode connection layer polar enhancement layer, a cathode translation layer, a cathode transition layer, a cathode sacrificial layer, a first blocking layer, a first grid drainage layer, a grid connection layer, a second blocking layer, a second grid drainage layer, a third blocking layer and a carbon nanotube. The flat plate display has the advantages of low cost, simple manufacturing process and stable and reliable manufacturing course.