Cd4051 Spice Model Link -

CD4051B data sheet, product information and support | TI.com

If you need a direct model link

: If your simulation doesn't strictly require the 20V range of the CD series, a model for the cd4051 spice model link

If you cannot find a specific CD4051 model, you can often use high-speed CMOS versions as a substitute for behavioral testing: CD4051B data sheet, product information and support | TI