本发明涉及一种低色号低VOC改性异氰酸酯的制备方法。该方法包含以下步骤：异氰酸酯单体在含磷催化剂的作用下反应得到改性异氰酸酯反应液；反应液中添加含硼化合物与含磷催化剂配位反应，得到改性异氰酸酯；任选的加入终止剂终止反应。该方法制备的改性异氰酸酯具有低色号、低VOC、保质期长，且在高温条件下稳定等优点。

The invention relates to a preparation method of modified isocyanate with low color number and low VOC. The method comprises the following steps: reacting an isocyanate monomer under the action of a phosphorus-containing catalyst to obtain a modified isocyanate reaction solution; adding a boron-containing compound into the reaction solution to carry out coordination reaction with a phosphorus-containing catalyst to obtain modified isocyanate; and optionally adding a terminating agent to terminate the reaction. The modified isocyanate prepared by the method has the advantages of low color number, low VOC, long shelf life, stability under a high-temperature condition and the like.