Using the cash- cash flow sensitivity model ,the relationship between political association, digital finance and the financing constraints was investigated by the data of 216 enterprises from 2011 to 2018 listed on the SME board and Growth Enterprise Board .The results show that the financial constraints on technology-based SMEs are common,political connections and digital finance development have ease the financing constraints of technology-based SMEs,Moreover, the development of digital finance narrows the difference in financing caused by political connections, showing stronger easing effect on financing constraints in the non-political connections sample.