High-purity (2 beta, 3 alpha, 5 alpha, 16 beta, 17 beta)-2-(4-morpholinyl)-16-(1-pyrrolidinyl)-androstane-3,17-diol or composition thereof and preparation method thereof

The invention relates to a high-purity (2 beta, 3 alpha, 5 alpha, 16 beta, 17 beta)-2-(4- morpholinyl)-16-(1-pyrrolidinyl)-androstane-3,17-diol or a composition thereof, a preparation method thereof (a compound shown in a formula III) or a composition thereof and application thereof to preparing rocuronium (a compound shown in a formula I). The method has good effect, low cost, high quality and simple and convenient operation and is suitable for large-scale industrial production; and the obtained product has high purity and stable properties.