A topology optimization design of continuum structures using node variable method was proposed not only to avoid the phenomenon of numerical instabilities but also to consider the manufacturing requirements. Within the defined sub-domain, the projection function independent on element mesh was adopted to represent the relationship of node design variables and node density variables. It could achieve the minimum length scale constraint of the topological solution to meet processing requirements. With the objective function developed by the minimum strain energy to meet stiffness requirement, and the volume used as the constraints, the topology optimization model of continuum structure under minimum length scale constraints was developed. The method of moving asymptotes was adopted to solve the topology optimization problem. The numerical examples indicated that the approach could avoid the phenomenon of numerical instabilities and obtain distinct topological structure which is convenient for manufacturing.