The invention provides a method for estimating horizontal dynamic displacement of a high-rise structure and a
monitoring system thereof. The invention belongs to the technical field of structural horizontal displacement monitoring. The method comprises the following steps: under normal wind load in a good environment, synchronously measuring the horizontal dynamic displacement ud (x, t) and an inclination angle utheta (x, t) changing along with time t at the x point of the structure for multiple times within a period of time t, wherein first-order
modal contribution plays a dominant role in the horizontal displacement of the structure under the action of wind load, and obtaining the horizontal dynamic displacement ud1 (x, t) and the inclination angle utheta 1 (x, t) under the first-order
modal respectively, wherein ud1 (x, t) = beta * utheta 1 (x, t) is met; performing
curve fitting on the horizontal dynamic displacement ud1 (x, t) and the inclination angle utheta1 (x, t) to obtain a
linear coefficient beta; under other wind loads, especially extreme wind loads, only measuring the inclination angle u theta S (x, t), changing along with time t, of the x point of the structure actually; reserving a first-order
modal contribution
signal u theta S1 (x, t); obtaining the real-time horizontal dynamic displacement udS1 (x, t) changing along with time t at the x point of the structure,and approximately estimating the real horizontal dynamic displacement udS (x, t) of the structure, so real-time
dynamic monitoring is achieved, calculation is convenient, precision is high, interference of environmental factors such as weather and
noise is avoided, and the accuracy of the monitoring structure is improved.