This paper introduces a new external uncertainty term into the traditional research model of the inter-temporal decision of household consumption and saving in life-cycle,which is different from most of previous relative researches considering only income uncertainty.Actually,the new uncertainty factor is a synthetic term of three subjectively perceived uncertainty terms (personal accidental expenditure,properties accidental expenditure and liability accidental expenditure) following different triangular distributions which could describe household membership subjective perception.Whats more,to get closer to reality,the CRRA (Constant Relative Risk Aversion) utility function with wealth accumulation motive is selected as the utility function,which has an elasticity notion of risk aversion and a description of desire to cumulate wealth.To solve the problem that it is hard to solve the optimal consumption and saving path under the situation above,the numerical simulation based on the 3-dimensional path planning algorithm of ant colony algorithm is introduced firstly in this paper,which is a famous method of solving optimal planning path that can build household decision-making information space and describe household decision-making mechanism better.At last,the simulations are set into two parts,namely single simulation and multiple simulations.In the former,optimal consumption path and wealth path under only income fluctuation are compared with the paths under both accidental expenditure and the same income fluctuation,from which it is achieved that the impact of accidental expenditure on the inter-temporal uncertainty decision of household consumption and saving in life-cycle; in the latter,three numerical simulations are conducted separately on the accidental expenditure with different distribution parameters under the same income fluctuation,from which this paper achieved different VaRs (Value at Risk) of household optimal consumption growth rate under different perceived triangular distribution.As a visual result,it can be showed that the dynamic impact of accidental expenditure on household optimal consumption and saving path,and the comparison between different VaRs can explain how the change of perceived parameters of triangular distribution of accidental expenditure would influence the household consumption growth rate VaR.