Against the background of intensified strategic competition among major powers，the geo-economic environment in Southeast Asia becomes more complicated and volatile：the regional economic game among extra-territorial big powers has continued to deepen，and the pressure on countries in the region to “choose sides” has been increasing；the “Indo-Pacific Economic Framework” has been released，and the competition in the regional economic order is becoming increasingly fierce；unbalanced economic development in the region has aggravated investment risks. From the perspective of system theory，China’s Southeast Asian economic diplomacy needs to rationally examine the changes of the geostrategic environment of the region，adjust the overall strategy framework in a timely manner，closely observe the effectiveness of the implementation of economic diplomacy decisions，and cope with “discourse traps” to achieve the optimization of decision-making. Specifically，China’s Southeast Asian economic diplomacy can guide the construction of the regional economic order with “harmonious culture” while opposing “alignment”，enhance inclusive regional economic cooperation centered on the Belt and Road and RCEP in response to the “Indo-Pacific Economic Framework”，and lead the practice of digital economy diplomacy to narrow the digital divide and improve the uneven development of Southeast Asian countries.