以我自己的组件react-better-countdown为例，
react-better-countdown首先在package.json里面添加types: types/index.d.ts，package.jsontypes: types/index.d.ts，
然后文件目录上添加对应文件夹和文件，

最后是index.d.ts文件的编写，具体看代码:index.d.ts
import * as React from 'react';

interface CountdownProps {

count?: number;

dayText?: string | React.ReactElement;

hourText?: string | React.ReactElement;

minuteText?: string | React.ReactElement;

secondText?: string | React.ReactElement;

callback?: Function;

className?: string;

style?: React.CSSProperties;

rest?: any
}

interface CountdownState {

count?: number;
}

declare module 'react-better-countdown' {

export default class Countdown extends React.Component {

state: CountdownState;

timer: null | number;

tick: () => void;

componentDidMount(): void;

componentDidUpdate(prevProps: CountdownProps): void;

componentWillUnmount(): void;

render: () => React.ReactElement;

}
}
import * as React from 'react';

interface CountdownProps {

count?: number;

dayText?: string | React.ReactElement;

hourText?: string | React.ReactElement;

minuteText?: string | React.ReactElement;

secondText?: string | React.ReactElement;

callback?: Function;

className?: string;

style?: React.CSSProperties;

rest?: any
}

interface CountdownState {

count?: number;
}

declare module 'react-better-countdown' {

export default class Countdown extends React.Component {

state: CountdownState;

timer: null | number;

tick: () => void;

componentDidMount(): void;

componentDidUpdate(prevProps: CountdownProps): void;

componentWillUnmount(): void;

render: () => React.ReactElement;

}
}详细代码看仓库：https://github.com/leeseean/react-better-countdown顺便求个Star！https://github.com/leeseean/react-better-countdown