The poor households are difficult to enter into financial market because of their absence of real right for mortgage credit, and financial poverty alleviation needs to solve credit allocation problem through credit enhancement mechanism. The farmers’ credit enhancement in practice mainly has two paths such as the credit enhancement based on rural external formal institution such as agricultural guaranteed insurance loan, and the credit enhancement based on rural inner informal institution such as farmers’ joint insurance loan. Agricultural guaranteed insurance loan system takes insurance contract as the mark of credit enhancement and is a kind of economic institutional arrangement based on legal contract, and its institutional insufficiency easily causes the low efficiency of cooperation game and inadequate incentive of demand. The farmers’ joint guaranteed loans take joint-repayment liability as guarantee constraint, are a kind of non-economic institutional arrangement by taking endogenous incentive mechanism of social capital as the core, and have both the advantage of credit discovery and monitoring and punishment and the collective default risk of farmers’ repayment. Under the objective of targeted poverty alleviation, Hunan’s guaranteed insurance loan model aiming at poverty alleviation projects is worth learning, however, the farmers’ joint insurance loan needs more model innovations such as encouraging rural elites to organize joint insurance groups with poor households and so on.