The invention relates to a split oscillation LED power constant current source, which can be widely applied to power supply configuration in the fields of indoor and outdoor LED illumination, chargerpower supplies, constant power AC-DC conversion, DC-DC conversion and the like. As shown in the figure, in a power-on state, if T1 is first turned on, the power supply voltage is obtained on R4, T2 isturned off, T1 is turned on by R3 and R6 in a DC positive bias stability mode, and then one route is that C3 is discharged through T1, C5, L2 and D2 loops, and the other route converts from a power supply positive pole to a power supply negative pole through T1, C5, L2, D2 and C4, when the capacitor C4 is charged to a potential close to R6, T1 is turned off slowly, the potential on R4 is lowered,T2 starts to be turned on, and through positive feedback, T2 is turned on completely and T1 is turned off completely to complete an oscillation cycle, and C5 obtains the output oscillation voltage.