A method of intra prediction for a picture block implemented by a decoding device, comprising: obtaining (1201, 1213) a value of a first indication information of a current block from a bitstream when the first indication information is present, or the value of the first indication information is inferred to be equal to 1 when the first indication information is not present in the bitstream, the value of the first indication information indicating whether an intra prediction mode of the current block is comprised in a set of most probable modes, wherein the set of most probable modes comprises 5 candidate intra prediction modes and Planar mode; obtaining a value of a reference index line of the current block from the bitstream when the value of the reference index line is present, or the value of the reference index line is inferred to be equal to 0 when the reference index line is not present in the bitstream; when the value of the first indication information indicates the intra prediction mode of the current block is comprised in the set of most probable modes, and when the value of the reference index line indicates the closest neighboring reference line to the current block is used, obtaining (1205, 1214) a value of a second indication information of the current block from the bitstream when the second indication information is present, or the value of the second indication information is inferred to be equal to 1 when the second indication information is not present in the bitstream, the value of the second indication information of the current block indicating whether the intra prediction mode of the current block is Planar mode or not, wherein the first indication information is indicated by a first flag intra_luma_mpm flag, and the second indication information is indicated by a second flag intra_luma_not_planar_flag, wherein when the value of intra_luma_mpm_flag equals to 1, the intra prediction mode of the current block is comprised in the set of most probable modes, and when the value of the reference index line of the current block equals to 0, the closest neighboring reference line to the current block is used, when the value of the second indication information of the current block indicating the intra prediction mode of the current block is not Planar mode, intra luma mpm idx corresponding to an index of the 5 candidate intra prediction modes is parsed, predicting the current block according to the index and entries of an MPM list. obtaining (1201, 1213) a value of a first indication information of a current block from a bitstream when the first indication information is present, or the value of the first indication information is inferred to be equal to 1 when the first indication information is not present in the bitstream, the value of the first indication information indicating whether an intra prediction mode of the current block is comprised in a set of most probable modes, wherein the set of most probable modes comprises 5 candidate intra prediction modes and Planar mode; obtaining a value of a reference index line of the current block from the bitstream when the value of the reference index line is present, or the value of the reference index line is inferred to be equal to 0 when the reference index line is not present in the bitstream; when the value of the first indication information indicates the intra prediction mode of the current block is comprised in the set of most probable modes, and when the value of the reference index line indicates the closest neighboring reference line to the current block is used, obtaining (1205, 1214) a value of a second indication information of the current block from the bitstream when the second indication information is present, or the value of the second indication information is inferred to be equal to 1 when the second indication information is not present in the bitstream, the value of the second indication information of the current block indicating whether the intra prediction mode of the current block is Planar mode or not, wherein the first indication information is indicated by a first flag intra_luma_mpm flag, and the second indication information is indicated by a second flag intra_luma_not_planar_flag, wherein when the value of intra_luma_mpm_flag equals to 1, the intra prediction mode of the current block is comprised in the set of most probable modes, and when the value of the reference index line of the current block equals to 0, the closest neighboring reference line to the current block is used, when the value of the second indication information of the current block indicating the intra prediction mode of the current block is not Planar mode, intra luma mpm idx corresponding to an index of the 5 candidate intra prediction modes is parsed, predicting the current block according to the index and entries of an MPM list.