Provided are two novel conotoxin peptides, namely É-CPTx-btl1 and É-CPTx-btl2, amino acid sequences thereof being shown as SEQ ID NO: 1 or 2 respectively. Also provided are polynucleotides coding these two peptides, constructs, expression vectors and transformed cells containing the polynucleotides, and preparation methods for the two peptides. The conotoxin peptides can be applied to treatment of calcium ion channel-related diseases.