The advancement of intelligent, extendable surface measurement, exemplified by high-speed railway and track detection, necessitates improvements in on-line measurement, efficiency, and accuracy. This requirement presents a new challenge to dynamic performance. Multiframe measurement methods using stereoscopic line-scan camera systems facilitates high-resolution and high-speed data acquisition. Similarly, the three-dimensional shape measurement method, which employs fringe projection with line-scan cameras, facilitates high-resolution and rapid data collection. These methods are advantageous for achieving high-quality three-dimensional reconstruction of extendable surfaces in motion. However, a robust fringe projection measurement method requires multiple frames to obtain accurate phase information, leading to low encoding efficiency. Thus, reducing the measurement period and decreasing the number of required image frames remain critical issues for enhancing dynamic performance. To mitigate these challenges, we introduced a dynamic measurement method for extendable surfaces using stereoscopic line-scan cameras and color-encoded three-frequency-fringe projection. We employed composite stripe projection based on color-structured light to minimize the number of projected patterns and three solid color images for effective crosstalk compensation. We sequentially projected a color-encoded sine fringe and white patterns onto the object, incorporating one-dimensional background normalization to mitigate the influence of the object's surface optical properties. This enables the acquisition of unwrapped phases based on color encoding information. Pixels in the images obtained from both cameras that share identical unwrapped phases are identified as corresponding pixels. The proposed method effectively exploits the dynamic capabilities of line-scan technology, thus achieving high-quality contour mapping through two frames and facilitating texture mapping.