After Sirisena was inaugurated as the president，he made the pledge to implement the “Hundred Days’ Reform” and has uphold the balancing diplomacy in foreign policy. Negative Trends present in the domestic and external environment of Sino-Sri Lankan relation. However，the promotion and implementation of the “21^st Century Maritime Silk Road” initiative closely align with the development strategy of Sri Lanka. Sino-Sri Lankan relation is faced with a major development opportunity. China and Sri Lanka will upgrade mutual trust，strengthen their ties in trade relations，accelerate cultural exchanges and have signed multiple framework documents in the development of bilateral relation，which will lay a solid foundation for the future development of Sino-Sri Lankan relation. Meanwhile，the geopolitical reality of the South Asian region and the deep influence of India on Sri Lanka also compose actual challenge to the development of Sino-Sri Lankan relation. The adjustment of Sri Lanka’s foreign policy will have duel effects on the development of Sino-Sri Lankan relation and significant implications to China’s promotion of the “21^st Century Maritime Silk Road” initiative. First，the pro-China policy of Rajapaksa will in the long run have more disadvantages than advantages to the “Maritime Silk Road” strategy of China due to the unsustainable political ecology and geo-factors. Second，the balancing diplomacy will be the diplomatic status quo of Sri Lanka and China must adapt to the adjustment of Sri Lanka’s foreign policy adjustment and take into consideration the “comfort level” of the corresponding countries. Third，the future development trend of the external environment of Sri Lanka is unfavorable to China，and China should have clear judgment on it. Fourth，the new government of Sri Lanka halted the Chinese cooperation project with the excuse of environmental impact and approval document for construction. This is an inevitable consequence of the new president of Sri Lanka trying to live up to his promise. The real goal is to settle the so called corruption of the former president，to crack down certain political powers within Sri Lanka and also to show “good will” to the external powers of India，Europe and USA. It can be predicted these behaviors are only temporary.