To study the sharing of tacit knowledge in SDN enterprise, a multi-dimensional tacit knowledge model is built at first. Then, as the way of tacit knowledge shared, blog system is researched to be interfaced into SDN enterprise system. The sharing study on tacit knowledge focuses on the realizing ideas and realizing codes of the enterprise management "blog" module which embodies the macro-management of sharing. For knowledge further shared, the macro-management is carried on through three guidance table for blog registering and classifying the signing up successfully blogs into three communities. This study presents the theory and method reference to the effective implementation of "blog" for the tacit knowledge sharing.