The big-headed turtle, Platysternon megacephalum, as the sole member of the monotypic family Platysternidae, has a number of distinct characteristics including an extra-large head, long tail, flat carapace, and a preference for low water temperature environments. We performed whole genome sequencing, assembly, and gene annotation of an adult male big-headed turtle based on the Illumina HiSeq X genomic sequencing platform. We generated ~497.1 Gb of raw sequencing data (×208.9 depth) and produced a draft genome with a total length of 2.32 Gb and contig and scaffold N50 sizes of 41.8 kb and 7.22 Mb, respectively. We also identified 924 Mb (39.84%) of repetitive sequences, 25,995 protein-coding genes, and 19,177 non-coding RNAs. We generated the first de novo genome of the big-headed turtle; these data will be essential to the further understanding and exploration of the genomic innovations and molecular mechanisms contributing to its unique morphology and physiological features.