In the past, urban climate problems caused by rapid urbanization, mainly urban heat island effect, affected people's daily life; under the background of new urbanization, people pay more attention to climate perception on human scale, and explore green and comfortable urban environment construction path and economic and effective urban cooling strategy. At present, the study of urban planning pays attention to macroscopic land use layout or microscopic landscape design but lacks the discussion on the influence of architectural layout on microclimate construction. Based on Grasshopper software, this paper constructs a microclimate analysis model of urban block scale and simulates the influence of different architectural layouts on urban microclimate in urban blocks by using control variable method. Through analysis, it is concluded that the microclimate of urban blocks is affected by building height, density, overhead rate of the first floor and building layout. Finally, the index optimization of urban design is proposed to improve the microclimate of blocks in urban planning and promote the construction of climate-adapted cities.