Abstract: An construction method of an embryonic chromosome signal library is provided. The construction method comprises obtaining an embryo and performing whole-genome amplification and next-generation sequencing to obtain a first chromosome signal; mapping the first chromosome signal to a chromosome reference signal to obtain a second chromosome signal; dividing the second chromosome signal within a predetermined interval range to obtain a third chromosome signal; and performing a regression correction on the sequencing read count (RC) of the third chromosome signal to obtain an embryonic chromosome signal library. Furthermore, a detection method and system of embryonic chromosomes are also provided. Thereby, the information comparison of the embryo chromosome signal library is used to determine whether the pre-implantation embryo is abnormal or not to achieve pre-implantation chromosome screening of pre-implantation embryos.