The invention discloses a red and orange light fluorescent powder with garnet structure. The fluorescent powder has a chemical expression of Mg3-xAxY2-y-cByAlz-aCaSi3-z-bDbO12-zEz:cCe<3+>, wherein A represents a composition of one or more than two selected from Ba, Sr and Ca in arbitrary proportion, B represents a composition one or more than two selected from Gd, La and Sc in arbitrary proportion, C represents Ga, D represents Ge, E represents F or Cl, x, y,z, a, b and c represent corresponding mole fractions and satisfy the relations of: 0<=x<0.35, 0<=y<0.35, 0<z<=2, 0<=a<0.5, 0<=b<0.35, 0<c<0.2, and z-a>0. Under the excitation of blue light in wavelength of 455nm, the yellow and orange light fluorescent powder has emission wavelength range of 500-750 nm, wherein the main emission wavelength range is 600-621 nm, the emission spectrum shows obvious redshift compared with YAG (delta S=45-85 nm), and the preparation temperature is low.