The present invention relates to the field of medical chemistry and discloses a preparation method for three crystal forms of cabazitaxel that is ester compound crystalline form J of cabazitaxel hydrate crystalline form G of cabazitaxel and crystalline form I of cabazitaxel and a novel crystalline form of cabazitaxel. The novel crystalline form of cabazitaxel according to the invention has good stability and good solubility in commonly used solvents and is easy to be preserved and is stable under treatment during preparation of dosage forms thus could be used for the preparation of drugs for treating prostate cancer.
