Aiming at the prominent problems of the spatial decoupling of road networks and functional facilities and the lack of group differentiated quantitative support in the evaluation of barrier-free moving lines in the aging reconstruction of existing communities, this study constructs a community barrier free accessible route evaluation and optimization model integrating point of interest (POI) data, space syntax and multi-objective optimization. Firstly, the importance weights of medical and healthcare, life service, and social leisure POIs and the Gaussian distance decay effect are introduced into the space syntax line segment model, and the POI weighted integration index is proposed, so that the centrality of the road structure and the attraction of facility functions can be expressed within the same framework. Secondly, based on 238 questionnaires and travel trajectory data of the elderly, a hierarchical behavioral impedance matrix was established for three groups: high activity group, low activity group, and wheelchair dependent group. Walking speed, slope tolerance, continuous walking distance, and visual continuity were included in the multidimensional accessibility measurement. Furthermore, node addition, road widening, and discontinuity connection are coded as hybrid decision variables. In order to maximize POI weighted integration degree and facility coverage degree and minimize renovation cost, an improved non dominated ranking genetic algorithm (mNSGA II) is proposed. The demand hierarchical Pareto ordering, spatial connectivity repair operator, and POI gravitational field initialization strategy are introduced. The case community verification shows that the fitting coefficient of the complete model for the actual travel heat of the elderly is 0.791, which is 64.1% higher than that of the traditional space syntax model. The Pareto frontier solution set obtained by mNSGA II improves by 43.0% and 9.1% in the inverted generational distance (IGD) and hypervolume (HV) metrics compared with the standard NSGA-II, respectively, and reduces the group payoff gap by 75.0%. After the optimization, the balanced scheme improves the POI weighted integration degree by 18.1%, the proportion of wheelchair accessible road network by 21.2 percentage points, and the spatial fairness by 31.5%. This study provides a set of quantifiable, verifiable and traceable system optimization tools for community aging environment design.