Based on the developing background of "Internet+" platform merging with traditional business, this paper analyzes the pricing strategies focusing on seller as a breakthrough for platform provider based on two-sided market, and finds that contrary to intuitive judgment, with favorable seller expectation, platform provider is supposed to commit to the price it will charge both sides with subsidies on transaction fee; while with unfavorable seller expectation, only price on seller side should be committed in the first stage, without price on buyer side, which should be confirmed in the second stage.