Dense WLAN networks have emerged as a promising design paradigm recently. While partially overlapped channels (POCs) have been proved to be able to improve the network capacity significantly in the dense network, they are usually considered given the fixed number of APs in traditional research works. The network capacity can be scaled by providing additional APs in a given area since the expected distance from users to the associated APs becomes shorter. On the other hand, the additional increment of network capacity by means of deploying more APs is limited. It can be accredited to the substantial interference among the high number of deployed APs assigned to POCs. Furthermore, the impact of POC model makes the design more complex. To cope with these challenges in this work, we study the problem of interaction between density of APs and POC assignment with parameter tuning. And propose the approach, called DAPA, in which we derive that the optimal density of APs lies in the feasible region consisting of the lower bound and upper bound density. Thus, the solution can be obtained by searching the feasible region by means of proposed POC assignment. Through analysis and numerical results in DAPA, we provide recommendations on the optimal dimension of high density and POC assignment with consideration of network configuration.