Three kinds of green light-emitting iridium complexes (Ⅲ,Ⅳ,Ⅴ) were designed and synthesized using 5-methyl-2-phenylpridine (CH3ppy) as main ligand, 3,7-diethyl-4,6-nonanedione (detd), 2,2,6,6-tetramethyl-3,5-heptanedione（tmd）and acetylacetone (acac) as three ancillary ligands (LX), respectively. These compounds were characterized by 1HNMR, elemental analysis. The maximum absorption wavelengths of compounds III, IV, and V measured by UV-vis spectrum were between 250nm and 280 nm, and the maximum emission wavelengths of compound III, IV, and V measured by fluorescence emission spectrum (PL) were 530.8nm, 534.2nm and 524.8nm. Phosphorescent organic light-emitting diodes with the prepared complexes were constructed. The configurations of the devices are ITO/HAT-CN (15nm)/TAPC (50nm)/TCTA (5nm)/TCTA: X (8%, 15 nm)/Bepp2 (35nm)/LiF (1nm)/Al(150nm). The device based on compound Ⅲ exhibits the best overall performance in three devices. It has a brightness of 59125.2 cd/m2. In addition, it shows a maximum external quantum efficiency of 15.0%, a maximum current efficiency of 53.8 cd/A, and a maximum power efficiency of 62.1 lm/W with chromaticity coordinates x=0.30,y=0.62.