A simple, novel atomic emission spectrometer (AES) based method for the determination of trace iron ion in water sample was proposed by atmospheric pressure glow discharge (APGD) coupled with photochemical vapor generation (PVG). The Fe solution mixed with formic acid was going through an ultraviolet (UV) lamp to generate volatile specie of iron and then entering the APGD excitation source for excitation and detection with microspectrometer. Several working conditions were optimized to acquire best analytical performance such as argon flow rate, sample flow rate, concentration of formic acid, pH value, and discharge current. The increase of argon flow rate, sample flow rate, and pH value along with the Fe signal intensity was increasing to a maximum value and then decreasing with similar trend. The optimal values of the argon flow rate, the sample flow rate, and the pH value were 300 mL·min-1, 2.6 mL·min-1, and 3.5, respectively. The Fe signal intensity increased with the increase of formic acid concentration from 10% to 50% (V/V) but the formic acid concentration with 40% (V/V) was selected when taking the stability of discharge into consideration. The Fe signal intensity decreased with the increase of discharge current from 10 to 35 mA. When the discharge current was below 10 mA, the plasma was unstable and easy to extinguish and the discharge current at 12 mA was selected. Under the optimal operating conditions, the detection limit (DL) for Fe (249.8 nm) was 2.1 μg·L-1 and the relative standard deviation (RSD) was 2.5% (n=9) with the proposed PVG-APGD-AES. The interferences caused by a series of metal elements including Cd2+, Mg2+, Ca2+, Au+, Zn2+, Mn2+, K+, As5+, Al3+, Cr3+, Ni2+, and Cu2+ in determining Fe using PVG-APGD-AES method were examined separately and the recoveries were all in the range of 87.6%～107.2%. The accuracy of the proposed method was validated by the determination of certified reference material (GSB 07-1188-2000) and the results agreed well with the certified value. The results suggested that the developed simple, robust, and cost-effective PVG-APGD-AES is promising for the determination of trace Fe in field.